diff --git a/app/models/theme.rb b/app/models/theme.rb
index 2fcd7c62417..88f794ad56b 100644
--- a/app/models/theme.rb
+++ b/app/models/theme.rb
@@ -857,10 +857,11 @@ class Theme < ActiveRecord::Base
     contents
   end
 
-  def migrate_settings(start_transaction: true)
+  def migrate_settings(start_transaction: true, fields: nil, allow_out_of_sequence_migration: false)
     block = -> do
       runner = ThemeSettingsMigrationsRunner.new(self)
-      results = runner.run
+      results =
+        runner.run(fields:, raise_error_on_out_of_sequence: !allow_out_of_sequence_migration)
 
       next if results.blank?
 
@@ -893,8 +894,12 @@ class Theme < ActiveRecord::Base
             name: res[:name],
             theme_field_id: res[:theme_field_id],
           )
+
         record.calculate_diff(res[:settings_before], res[:settings_after])
-        record.save!
+
+        # If out of sequence migration is allowed we don't want to raise an error if the record is invalid due to version
+        # conflicts
+        allow_out_of_sequence_migration ? record.save : record.save!
       end
 
       self.reload
diff --git a/app/models/theme_settings_migration.rb b/app/models/theme_settings_migration.rb
index a93d11db670..3cae4b7e969 100644
--- a/app/models/theme_settings_migration.rb
+++ b/app/models/theme_settings_migration.rb
@@ -4,7 +4,7 @@ class ThemeSettingsMigration < ActiveRecord::Base
   belongs_to :theme
   belongs_to :theme_field
 
-  validates :theme_id, presence: true
+  validates :theme_id, presence: true, uniqueness: { scope: :version }
   validates :theme_field_id, presence: true
 
   validates :version, presence: true
diff --git a/app/services/theme_settings_migrations_runner.rb b/app/services/theme_settings_migrations_runner.rb
index 6a8c04307da..223ceea66f3 100644
--- a/app/services/theme_settings_migrations_runner.rb
+++ b/app/services/theme_settings_migrations_runner.rb
@@ -53,7 +53,7 @@ class ThemeSettingsMigrationsRunner
     }
   JS
 
-  private_constant :Migration, :MIGRATION_ENTRY_POINT_JS
+  private_constant :MIGRATION_ENTRY_POINT_JS
 
   def self.loader_js_lib_content
     @loader_js_lib_content ||=
@@ -67,8 +67,8 @@ class ThemeSettingsMigrationsRunner
     @memory = memory
   end
 
-  def run
-    fields = lookup_pending_migrations_fields
+  def run(fields: nil, raise_error_on_out_of_sequence: true)
+    fields ||= lookup_pending_migrations_fields
 
     count = fields.count
     return [] if count == 0
@@ -80,12 +80,13 @@ class ThemeSettingsMigrationsRunner
 
     current_migration_version =
       @theme.theme_settings_migrations.order(version: :desc).pick(:version)
+
     current_migration_version ||= -Float::INFINITY
 
     current_settings = lookup_overriden_settings
 
     migrations.map do |migration|
-      if migration.version <= current_migration_version
+      if migration.version <= current_migration_version && raise_error_on_out_of_sequence
         raise_error(
           "themes.import_error.migrations.out_of_sequence",
           name: migration.original_name,
@@ -94,6 +95,7 @@ class ThemeSettingsMigrationsRunner
       end
 
       migrated_settings = execute(migration, current_settings)
+
       results = {
         version: migration.version,
         name: migration.name,
@@ -157,6 +159,7 @@ class ThemeSettingsMigrationsRunner
       .migration_fields
       .left_joins(:theme_settings_migration)
       .where(theme_settings_migration: { id: nil })
+      .order(created_at: :asc)
   end
 
   def convert_fields_to_migrations(fields)
diff --git a/spec/models/theme_spec.rb b/spec/models/theme_spec.rb
index 9d77da0e167..9e8faf0dc1d 100644
--- a/spec/models/theme_spec.rb
+++ b/spec/models/theme_spec.rb
@@ -341,10 +341,10 @@ HTML
       expect(scss).to include("font-size:30px")
 
       # Escapes correctly. If not, compiling this would throw an exception
-      setting.value = <<~CSS
+      setting.value = <<~SCSS
           \#{$fakeinterpolatedvariable}
           andanothervalue 'withquotes'; margin: 0;
-      CSS
+      SCSS
 
       theme.set_field(target: :common, name: :scss, value: "body {font-size: quote($font-size)}")
       theme.save!
@@ -1347,6 +1347,55 @@ HTML
         "deletions" => [{ "key" => "setting_that_will_be_removed", "val" => 1023 }],
       )
     end
+
+    it "does not raise an out of sequence error and does not create `ThemeSettingsMigration` record for out of sequence migration when `allow_out_of_sequence_migration` kwarg is set to true" do
+      second_migration_field =
+        Fabricate(
+          :migration_theme_field,
+          name: "0001-some-other-migration-name",
+          theme: theme,
+          value: <<~JS,
+          export default function migrate(settings) {
+            settings.set("integer_setting", 3);
+            return settings;
+          }
+        JS
+          version: 1,
+        )
+
+      expect do theme.migrate_settings end.to raise_error(
+        Theme::SettingsMigrationError,
+        /'0001-some-other-migration-name' is out of sequence/,
+      )
+
+      expect(theme.get_setting("integer_setting")).to eq(1)
+
+      theme.migrate_settings(allow_out_of_sequence_migration: true)
+
+      expect(theme.theme_settings_migrations.count).to eq(1)
+      expect(theme.theme_settings_migrations.first.theme_field_id).to eq(migration_field.id)
+      expect(theme.get_setting("integer_setting")).to eq(3)
+    end
+
+    it "allows custom migration fields to be run by specifing the `fields` kwarg" do
+      expect do theme.migrate_settings(fields: []) end.not_to change {
+        theme.theme_settings_migrations.count
+      }
+
+      second_migration_field =
+        Fabricate(:migration_theme_field, theme: theme, value: <<~JS, version: 2)
+          export default function migrate(settings) {
+            settings.set("integer_setting", 3);
+            return settings;
+          }
+        JS
+
+      theme.migrate_settings(fields: [second_migration_field])
+
+      expect(theme.theme_settings_migrations.count).to eq(1)
+      expect(theme.theme_settings_migrations.first.theme_field_id).to eq(second_migration_field.id)
+      expect(theme.get_setting("integer_setting")).to eq(3)
+    end
   end
 
   describe "development experience" do
diff --git a/spec/support/helpers.rb b/spec/support/helpers.rb
index 3657886dd58..31d49528322 100644
--- a/spec/support/helpers.rb
+++ b/spec/support/helpers.rb
@@ -229,4 +229,70 @@ module Helpers
   ensure
     SearchIndexer.disable
   end
+
+  # Uploads a theme from a directory.
+  #
+  # @param set_theme_as_default [Boolean] Whether to set the uploaded theme as the default theme for the site. Defaults to true.
+  #
+  # @return [Theme] The uploaded theme model given by `models/theme.rb`.
+  #
+  # @example Upload a theme and set it as default
+  #   upload_theme("/path/to/theme")
+  def upload_theme(set_theme_as_default: true)
+    theme = RemoteTheme.import_theme_from_directory(theme_dir_from_caller)
+
+    if theme.component
+      raise "Uploaded theme is a theme component, please use the `upload_theme_component` method instead."
+    end
+
+    theme.set_default! if set_theme_as_default
+    theme
+  end
+
+  # Uploads a theme component from a directory.
+  #
+  # @param parent_theme_id [Integer] The ID of the theme to add the theme component to. Defaults to `SiteSetting.default_theme_id`.
+  #
+  # @return [Theme] The uploaded theme model given by `models/theme.rb`.
+  #
+  # @example Upload a theme component
+  #   upload_theme_component("/path/to/theme_component")
+  #
+  # @example Upload a theme component and add it to a specific theme
+  #   upload_theme_component("/path/to/theme_component", parent_theme_id: 123)
+  def upload_theme_component(parent_theme_id: SiteSetting.default_theme_id)
+    theme = RemoteTheme.import_theme_from_directory(theme_dir_from_caller)
+
+    if !theme.component
+      raise "Uploaded theme is not a theme component, please use the `upload_theme` method instead."
+    end
+
+    Theme.find(parent_theme_id).child_themes << theme
+    theme
+  end
+
+  # Runs named migration for a given theme.
+  #
+  # @params [Theme] theme The theme to run the migration for.
+  # @params [String] migration_name The name of the migration to run.
+  #
+  # @return [nil]
+  #
+  # @example
+  #   run_theme_migration(theme, "0001-migrate-some-settings")
+  def run_theme_migration(theme, migration_name)
+    migration_theme_field = theme.theme_fields.find_by(name: migration_name)
+    theme.migrate_settings(fields: [migration_theme_field], allow_out_of_sequence_migration: true)
+    nil
+  end
+
+  private
+
+  def theme_dir_from_caller
+    caller.each do |line|
+      if (split = line.split(%r{/spec/*/.+_spec.rb})).length > 1
+        return split.first
+      end
+    end
+  end
 end
diff --git a/spec/support/system_helpers.rb b/spec/support/system_helpers.rb
index 3eb1b10967c..22ab72411fe 100644
--- a/spec/support/system_helpers.rb
+++ b/spec/support/system_helpers.rb
@@ -22,47 +22,6 @@ module SystemHelpers
     expect(page).to have_content("Signed in to #{user.encoded_username} successfully")
   end
 
-  # Uploads a theme from a directory.
-  #
-  # @param set_theme_as_default [Boolean] Whether to set the uploaded theme as the default theme for the site. Defaults to true.
-  #
-  # @return [Theme] The uploaded theme model given by `models/theme.rb`.
-  #
-  # @example Upload a theme and set it as default
-  #   upload_theme("/path/to/theme")
-  def upload_theme(set_theme_as_default: true)
-    theme = RemoteTheme.import_theme_from_directory(theme_dir_from_caller)
-
-    if theme.component
-      raise "Uploaded theme is a theme component, please use the `upload_theme_component` method instead."
-    end
-
-    theme.set_default! if set_theme_as_default
-    theme
-  end
-
-  # Uploads a theme component from a directory.
-  #
-  # @param parent_theme_id [Integer] The ID of the theme to add the theme component to. Defaults to `SiteSetting.default_theme_id`.
-  #
-  # @return [Theme] The uploaded theme model given by `models/theme.rb`.
-  #
-  # @example Upload a theme component
-  #   upload_theme_component("/path/to/theme_component")
-  #
-  # @example Upload a theme component and add it to a specific theme
-  #   upload_theme_component("/path/to/theme_component", parent_theme_id: 123)
-  def upload_theme_component(parent_theme_id: SiteSetting.default_theme_id)
-    theme = RemoteTheme.import_theme_from_directory(theme_dir_from_caller)
-
-    if !theme.component
-      raise "Uploaded theme is not a theme component, please use the `upload_theme` method instead."
-    end
-
-    Theme.find(parent_theme_id).child_themes << theme
-    theme
-  end
-
   def setup_system_test
     SiteSetting.login_required = false
     SiteSetting.has_login_hint = false
@@ -205,14 +164,4 @@ module SystemHelpers
       )
     end
   end
-
-  private
-
-  def theme_dir_from_caller
-    caller.each do |line|
-      if (split = line.split(%r{/spec/system/.+_spec.rb})).length > 1
-        return split.first
-      end
-    end
-  end
 end