diff --git a/app/BUILD.gn b/app/BUILD.gn
index 5ba3fc0ca92e..76070554cc9c 100644
--- a/app/BUILD.gn
+++ b/app/BUILD.gn
@@ -120,6 +120,7 @@ source_set("unit_tests") {
   deps = [
     "//base",
     "//base/test:test_support",
+    "//brave/components/variations:buildflags",
     "//chrome/browser",
     "//chrome/browser/enterprise/connectors/analysis:features",
     "//chrome/browser/ui",
diff --git a/app/brave_main_delegate.cc b/app/brave_main_delegate.cc
index bdb0f0956234..b926a3d5fb10 100644
--- a/app/brave_main_delegate.cc
+++ b/app/brave_main_delegate.cc
@@ -22,7 +22,7 @@
 #include "brave/components/constants/brave_switches.h"
 #include "brave/components/speedreader/common/buildflags/buildflags.h"
 #include "brave/components/update_client/buildflags.h"
-#include "brave/components/variations/buildflags.h"
+#include "brave/components/variations/command_line_utils.h"
 #include "brave/renderer/brave_content_renderer_client.h"
 #include "brave/utility/brave_content_utility_client.h"
 #include "build/build_config.h"
@@ -35,7 +35,6 @@
 #include "components/dom_distiller/core/dom_distiller_switches.h"
 #include "components/embedder_support/switches.h"
 #include "components/sync/base/command_line_switches.h"
-#include "components/variations/variations_switches.h"
 #include "google_apis/gaia/gaia_switches.h"
 
 #if BUILDFLAG(IS_LINUX)
@@ -169,21 +168,7 @@ void BraveMainDelegate::AppendCommandLineOptions() {
                                     brave_sync_service_url.c_str());
   }
 
-  // Brave variations
-  if (!command_line->HasSwitch(variations::switches::kVariationsServerURL)) {
-    command_line->AppendSwitchASCII(variations::switches::kVariationsServerURL,
-                                    BUILDFLAG(BRAVE_VARIATIONS_SERVER_URL));
-  }
-  // Insecure fall-back for variations is set to the same (secure) URL. This is
-  // done so that if VariationsService tries to fall back to insecure url the
-  // check for kHttpScheme in VariationsService::MaybeRetryOverHTTP would
-  // prevent it from doing so as we don't want to use an insecure fall-back.
-  if (!command_line->HasSwitch(
-          variations::switches::kVariationsInsecureServerURL)) {
-    command_line->AppendSwitchASCII(
-        variations::switches::kVariationsInsecureServerURL,
-        BUILDFLAG(BRAVE_VARIATIONS_SERVER_URL));
-  }
+  variations::AppendBraveCommandLineOptions(*command_line);
 }
 
 std::optional<int> BraveMainDelegate::BasicStartupComplete() {
diff --git a/app/brave_main_delegate_unittest.cc b/app/brave_main_delegate_unittest.cc
index e9e0918ad174..956438e84e39 100644
--- a/app/brave_main_delegate_unittest.cc
+++ b/app/brave_main_delegate_unittest.cc
@@ -46,16 +46,9 @@ TEST(BraveMainDelegateUnitTest, OverrideSwitchFromCommandLine) {
   base::CommandLine& command_line = *base::CommandLine::ForCurrentProcess();
   const std::string override_sync_url = "https://sync.com";
   const std::string override_origin_trials_public_key = "public_key";
-  const std::string override_variations_url = "https://variations.com";
-  const std::string override_insecure_variations_url = "https://variations.com";
   command_line.AppendSwitchASCII(syncer::kSyncServiceURL, override_sync_url);
   command_line.AppendSwitchASCII(embedder_support::kOriginTrialPublicKey,
                                  override_origin_trials_public_key);
-  command_line.AppendSwitchASCII(variations::switches::kVariationsServerURL,
-                                 override_variations_url);
-  command_line.AppendSwitchASCII(
-      variations::switches::kVariationsInsecureServerURL,
-      override_insecure_variations_url);
 
   BraveMainDelegate::AppendCommandLineOptions();
 
@@ -66,14 +59,4 @@ TEST(BraveMainDelegateUnitTest, OverrideSwitchFromCommandLine) {
       override_origin_trials_public_key.c_str(),
       command_line.GetSwitchValueASCII(embedder_support::kOriginTrialPublicKey)
           .c_str());
-  ASSERT_STREQ(
-      override_variations_url.c_str(),
-      command_line
-          .GetSwitchValueASCII(variations::switches::kVariationsServerURL)
-          .c_str());
-  ASSERT_STREQ(override_insecure_variations_url.c_str(),
-               command_line
-                   .GetSwitchValueASCII(
-                       variations::switches::kVariationsInsecureServerURL)
-                   .c_str());
 }
diff --git a/browser/sources.gni b/browser/sources.gni
index ab87ca04bfce..5936aa9d47db 100644
--- a/browser/sources.gni
+++ b/browser/sources.gni
@@ -446,7 +446,7 @@ if (is_win && is_official_build) {
 brave_chrome_browser_public_deps = [
   "//brave/browser:browser_process",
   "//brave/components/brave_sync:constants",
-  "//brave/components/variations:constants",
+  "//brave/components/variations",
 ]
 
 if (is_mac) {
diff --git a/chromium_src/components/version_ui/version_handler_helper.cc b/chromium_src/components/version_ui/version_handler_helper.cc
index 5b1727d4c674..57466edd8fb0 100644
--- a/chromium_src/components/version_ui/version_handler_helper.cc
+++ b/chromium_src/components/version_ui/version_handler_helper.cc
@@ -25,8 +25,13 @@ base::Value::List GetVariationsList() {
   }
 
   base::Value::List variations_list;
-  for (std::string& variation : variations)
+  const std::string& seed_version = variations::GetSeedVersion();
+  if (!seed_version.empty() && seed_version != "1") {
+    variations_list.Append(seed_version);
+  }
+  for (std::string& variation : variations) {
     variations_list.Append(std::move(variation));
+  }
 
   return variations_list;
 }
diff --git a/components/variations/BUILD.gn b/components/variations/BUILD.gn
index d624aaa14430..74e362cb28a4 100644
--- a/components/variations/BUILD.gn
+++ b/components/variations/BUILD.gn
@@ -11,6 +11,30 @@ buildflag_header("buildflags") {
   flags = [ "BRAVE_VARIATIONS_SERVER_URL=\"$brave_variations_server_url\"" ]
 }
 
-group("constants") {
-  public_deps = [ ":buildflags" ]
+static_library("variations") {
+  sources = [
+    "command_line_utils.cc",
+    "command_line_utils.h",
+    "switches.h",
+  ]
+
+  deps = [
+    ":buildflags",
+    "//base",
+    "//components/variations",
+  ]
+}
+
+source_set("unit_tests") {
+  testonly = true
+
+  sources = [ "command_line_utils_unittest.cc" ]
+
+  deps = [
+    ":buildflags",
+    ":variations",
+    "//base",
+    "//components/variations",
+    "//testing/gtest",
+  ]
 }
diff --git a/components/variations/command_line_utils.cc b/components/variations/command_line_utils.cc
new file mode 100644
index 000000000000..8994aec5399d
--- /dev/null
+++ b/components/variations/command_line_utils.cc
@@ -0,0 +1,63 @@
+// Copyright (c) 2024 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+#include "brave/components/variations/command_line_utils.h"
+
+#include <string>
+
+#include "base/command_line.h"
+#include "base/strings/string_util.h"
+#include "brave/components/variations/buildflags.h"
+#include "brave/components/variations/switches.h"
+#include "components/variations/variations_switches.h"
+
+namespace variations {
+
+namespace {
+
+// A GitHub workflow in the brave/brave-variations repository generates the test
+// seed and uploads it to a URL with the following template, where $1 is the
+// pull request number.
+constexpr char kVariationsPrTestSeedUrlTemplate[] =
+    "https://griffin.brave.com/pull/$1/seed";
+
+}  // namespace
+
+void AppendBraveCommandLineOptions(base::CommandLine& command_line) {
+  std::string variations_server_url = BUILDFLAG(BRAVE_VARIATIONS_SERVER_URL);
+
+  if (command_line.HasSwitch(switches::kVariationsPR)) {
+    variations_server_url = base::ReplaceStringPlaceholders(
+        kVariationsPrTestSeedUrlTemplate,
+        {command_line.GetSwitchValueASCII(switches::kVariationsPR)}, nullptr);
+
+    // Generated seed is not signed, so we need to disable signature check.
+    command_line.AppendSwitch(
+        variations::switches::kAcceptEmptySeedSignatureForTesting);
+
+    // Disable fetch throttling to force the fetch at startup on mobile
+    // platforms.
+    command_line.AppendSwitch(
+        variations::switches::kDisableVariationsSeedFetchThrottling);
+  }
+
+  if (!command_line.HasSwitch(variations::switches::kVariationsServerURL)) {
+    command_line.AppendSwitchASCII(variations::switches::kVariationsServerURL,
+                                   variations_server_url);
+  }
+
+  // Insecure fall-back for variations is set to the same (secure) URL. This
+  // is done so that if VariationsService tries to fall back to insecure url
+  // the check for kHttpScheme in VariationsService::MaybeRetryOverHTTP would
+  // prevent it from doing so as we don't want to use an insecure fall-back.
+  if (!command_line.HasSwitch(
+          variations::switches::kVariationsInsecureServerURL)) {
+    command_line.AppendSwitchASCII(
+        variations::switches::kVariationsInsecureServerURL,
+        variations_server_url);
+  }
+}
+
+}  // namespace variations
diff --git a/components/variations/command_line_utils.h b/components/variations/command_line_utils.h
new file mode 100644
index 000000000000..88844027cf3f
--- /dev/null
+++ b/components/variations/command_line_utils.h
@@ -0,0 +1,21 @@
+// Copyright (c) 2024 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+#ifndef BRAVE_COMPONENTS_VARIATIONS_COMMAND_LINE_UTILS_H_
+#define BRAVE_COMPONENTS_VARIATIONS_COMMAND_LINE_UTILS_H_
+
+namespace base {
+class CommandLine;
+}
+
+namespace variations {
+
+// Appends Brave-specific command line options to fetch variations seed from the
+// correct server.
+void AppendBraveCommandLineOptions(base::CommandLine& command_line);
+
+}  // namespace variations
+
+#endif  // BRAVE_COMPONENTS_VARIATIONS_COMMAND_LINE_UTILS_H_
diff --git a/components/variations/command_line_utils_unittest.cc b/components/variations/command_line_utils_unittest.cc
new file mode 100644
index 000000000000..705a06cf76f6
--- /dev/null
+++ b/components/variations/command_line_utils_unittest.cc
@@ -0,0 +1,70 @@
+// Copyright (c) 2024 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+#include "brave/components/variations/command_line_utils.h"
+
+#include <string>
+
+#include "base/command_line.h"
+#include "brave/components/variations/buildflags.h"
+#include "brave/components/variations/switches.h"
+#include "components/variations/variations_switches.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace variations {
+
+TEST(VariationsCommandLineUtils, DefaultVariationsServerUrl) {
+  base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+  AppendBraveCommandLineOptions(command_line);
+
+  EXPECT_EQ(command_line.GetSwitchValueASCII(
+                variations::switches::kVariationsServerURL),
+            BUILDFLAG(BRAVE_VARIATIONS_SERVER_URL));
+  EXPECT_EQ(command_line.GetSwitchValueASCII(
+                variations::switches::kVariationsInsecureServerURL),
+            BUILDFLAG(BRAVE_VARIATIONS_SERVER_URL));
+  EXPECT_FALSE(command_line.HasSwitch(
+      variations::switches::kAcceptEmptySeedSignatureForTesting));
+  EXPECT_FALSE(command_line.HasSwitch(
+      variations::switches::kDisableVariationsSeedFetchThrottling));
+}
+
+TEST(VariationsCommandLineUtils, OverrideVariationsServerUrl) {
+  base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+  const std::string override_variations_url = "https://variations.com";
+  const std::string override_insecure_variations_url = "http://insecure.com";
+  command_line.AppendSwitchASCII(variations::switches::kVariationsServerURL,
+                                 override_variations_url);
+  command_line.AppendSwitchASCII(
+      variations::switches::kVariationsInsecureServerURL,
+      override_insecure_variations_url);
+  AppendBraveCommandLineOptions(command_line);
+
+  EXPECT_EQ(override_variations_url,
+            command_line.GetSwitchValueASCII(
+                variations::switches::kVariationsServerURL));
+  EXPECT_EQ(override_insecure_variations_url,
+            command_line.GetSwitchValueASCII(
+                variations::switches::kVariationsInsecureServerURL));
+}
+
+TEST(VariationsCommandLineUtils, SetVariationsPrParameter) {
+  base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+  command_line.AppendSwitchASCII(variations::switches::kVariationsPR, "1234");
+  AppendBraveCommandLineOptions(command_line);
+
+  EXPECT_EQ(command_line.GetSwitchValueASCII(
+                variations::switches::kVariationsServerURL),
+            "https://griffin.brave.com/pull/1234/seed");
+  EXPECT_EQ(command_line.GetSwitchValueASCII(
+                variations::switches::kVariationsInsecureServerURL),
+            "https://griffin.brave.com/pull/1234/seed");
+  EXPECT_TRUE(command_line.HasSwitch(
+      variations::switches::kAcceptEmptySeedSignatureForTesting));
+  EXPECT_TRUE(command_line.HasSwitch(
+      variations::switches::kDisableVariationsSeedFetchThrottling));
+}
+
+}  // namespace variations
diff --git a/components/variations/switches.h b/components/variations/switches.h
new file mode 100644
index 000000000000..93f0d5d9580c
--- /dev/null
+++ b/components/variations/switches.h
@@ -0,0 +1,18 @@
+// Copyright (c) 2024 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this file,
+// You can obtain one at https://mozilla.org/MPL/2.0/.
+
+#ifndef BRAVE_COMPONENTS_VARIATIONS_SWITCHES_H_
+#define BRAVE_COMPONENTS_VARIATIONS_SWITCHES_H_
+
+namespace variations::switches {
+
+// If this flag is set to a brave/brave-variations pull request number, the
+// browser will point "--variations-server-url" to a test seed URL from this
+// pull request.
+inline constexpr char kVariationsPR[] = "variations-pr";
+
+}  // namespace variations::switches
+
+#endif  // BRAVE_COMPONENTS_VARIATIONS_SWITCHES_H_
diff --git a/ios/app/BUILD.gn b/ios/app/BUILD.gn
index 9bff336d3663..12f8958a1f4d 100644
--- a/ios/app/BUILD.gn
+++ b/ios/app/BUILD.gn
@@ -35,7 +35,7 @@ source_set("app") {
     "//brave/components/p3a:buildflags",
     "//brave/components/skus/browser",
     "//brave/components/update_client:buildflags",
-    "//brave/components/variations:constants",
+    "//brave/components/variations",
     "//brave/ios/app/resources",
     "//brave/ios/browser",
     "//brave/ios/browser/api/ads",
diff --git a/ios/app/brave_core_switches.h b/ios/app/brave_core_switches.h
index b2af640dce3f..d5fb933c5c25 100644
--- a/ios/app/brave_core_switches.h
+++ b/ios/app/brave_core_switches.h
@@ -24,6 +24,11 @@ OBJC_EXPORT const BraveCoreSwitchKey BraveCoreSwitchKeyVModule;
 ///
 /// Expected value: A URL string
 OBJC_EXPORT const BraveCoreSwitchKey BraveCoreSwitchKeySyncURL;
+/// Sets the variations URL to a test seed generated in brave/brave-variations
+/// pull request.
+///
+/// Expected value: A brave/brave-variations pull request number
+OBJC_EXPORT const BraveCoreSwitchKey BraveCoreSwitchKeyVariationsPR;
 /// Overrides the variations seed URL. Defaults to production
 ///
 /// Expected value: A URL string
diff --git a/ios/app/brave_core_switches.mm b/ios/app/brave_core_switches.mm
index e339a165c775..bedf69c1fa54 100644
--- a/ios/app/brave_core_switches.mm
+++ b/ios/app/brave_core_switches.mm
@@ -9,6 +9,7 @@
 #include "base/strings/sys_string_conversions.h"
 #include "brave/components/brave_component_updater/browser/switches.h"
 #include "brave/components/p3a/switches.h"
+#include "brave/components/variations/switches.h"
 #include "components/component_updater/component_updater_switches.h"
 #include "components/sync/base/command_line_switches.h"
 #include "components/variations/variations_switches.h"
@@ -23,6 +24,8 @@
     base::SysUTF8ToNSString(switches::kVModule);
 const BraveCoreSwitchKey BraveCoreSwitchKeySyncURL =
     base::SysUTF8ToNSString(syncer::kSyncServiceURL);
+const BraveCoreSwitchKey BraveCoreSwitchKeyVariationsPR =
+    base::SysUTF8ToNSString(variations::switches::kVariationsPR);
 const BraveCoreSwitchKey BraveCoreSwitchKeyVariationsURL =
     base::SysUTF8ToNSString(variations::switches::kVariationsServerURL);
 // There is no exposed switch for rewards
diff --git a/ios/app/brave_main_delegate.mm b/ios/app/brave_main_delegate.mm
index 0fc0c8c81d05..da9d1aff6274 100644
--- a/ios/app/brave_main_delegate.mm
+++ b/ios/app/brave_main_delegate.mm
@@ -16,7 +16,7 @@
 #include "brave/components/brave_component_updater/browser/switches.h"
 #include "brave/components/brave_sync/buildflags.h"
 #include "brave/components/update_client/buildflags.h"
-#include "brave/components/variations/buildflags.h"
+#include "brave/components/variations/command_line_utils.h"
 #include "components/browser_sync/browser_sync_switches.h"
 #include "components/component_updater/component_updater_switches.h"
 #include "components/sync/base/command_line_switches.h"
@@ -72,19 +72,7 @@ @implementation BundleLookupClass
                                     BUILDFLAG(BRAVE_SYNC_ENDPOINT));
   }
 
-  // Brave variations
-  if (!command_line->HasSwitch(variations::switches::kVariationsServerURL)) {
-    command_line->AppendSwitchASCII(variations::switches::kVariationsServerURL,
-                                    BUILDFLAG(BRAVE_VARIATIONS_SERVER_URL));
-
-    // Insecure fall-back for variations is set to the same (secure) URL. This
-    // is done so that if VariationsService tries to fall back to insecure url
-    // the check for kHttpScheme in VariationsService::MaybeRetryOverHTTP would
-    // prevent it from doing so as we don't want to use an insecure fall-back.
-    command_line->AppendSwitchASCII(
-        variations::switches::kVariationsInsecureServerURL,
-        BUILDFLAG(BRAVE_VARIATIONS_SERVER_URL));
-  }
+  variations::AppendBraveCommandLineOptions(*command_line);
 
   if (!command_line->HasSwitch(switches::kVModule)) {
     command_line->AppendSwitchASCII(switches::kVModule, "*/brave/*=0");
diff --git a/ios/brave-ios/Sources/Brave/Frontend/Settings/Debug/BraveCoreDebugSwitchesView.swift b/ios/brave-ios/Sources/Brave/Frontend/Settings/Debug/BraveCoreDebugSwitchesView.swift
index 90a74dd96cfc..21aff7bab7cb 100644
--- a/ios/brave-ios/Sources/Brave/Frontend/Settings/Debug/BraveCoreDebugSwitchesView.swift
+++ b/ios/brave-ios/Sources/Brave/Frontend/Settings/Debug/BraveCoreDebugSwitchesView.swift
@@ -17,6 +17,8 @@ extension BraveCoreSwitchKey {
       return "Component Updater"
     case .syncURL:
       return "Sync URL"
+    case .variationsPR:
+      return "Variations PR"
     case .variationsURL:
       return "Variations URL"
     case .p3aDoNotRandomizeUploadInterval:
@@ -317,14 +319,18 @@ struct BraveCoreDebugSwitchesView: View {
       }
       Section {
         Group {
-          // Sync URL
           NavigationLink {
             BasicStringInputView(coreSwitch: .syncURL)
               .keyboardType(.URL)
           } label: {
             SwitchContainer(.syncURL)
           }
-          // Variations URL
+          NavigationLink {
+            BasicStringInputView(coreSwitch: .variationsPR)
+              .keyboardType(.numberPad)
+          } label: {
+            SwitchContainer(.variationsPR)
+          }
           NavigationLink {
             BasicStringInputView(coreSwitch: .variationsURL)
               .keyboardType(.URL)
diff --git a/test/BUILD.gn b/test/BUILD.gn
index cab56ae22bb9..2f700833b790 100644
--- a/test/BUILD.gn
+++ b/test/BUILD.gn
@@ -265,6 +265,7 @@ test("brave_unit_tests") {
     "//brave/components/time_period_storage",
     "//brave/components/tor/buildflags",
     "//brave/components/url_sanitizer/browser:unittests",
+    "//brave/components/variations:unit_tests",
     "//brave/components/version_info:unit_tests",
     "//brave/extensions:common",
     "//brave/mojo/brave_ast_patcher:unit_tests",