diff --git a/app/models/category.rb b/app/models/category.rb
index 9a83488fc..c4239879d 100644
--- a/app/models/category.rb
+++ b/app/models/category.rb
@@ -109,6 +109,14 @@ class Category < ApplicationRecord
       I18n.t(UNCATEGORIZED_NAME_KEY)
     end
 
+    # Returns all possible uncategorized names across all supported locales
+    # Used to detect uncategorized filter regardless of URL parameter language
+    def all_uncategorized_names
+      LanguagesHelper::SUPPORTED_LOCALES.map do |locale|
+        I18n.t(UNCATEGORIZED_NAME_KEY, locale: locale)
+      end.uniq
+    end
+
     # Helper to get the localized name for other investments
     def other_investments_name
       I18n.t(OTHER_INVESTMENTS_NAME_KEY)
diff --git a/app/models/transaction/search.rb b/app/models/transaction/search.rb
index 287dae467..1bee4ecb6 100644
--- a/app/models/transaction/search.rb
+++ b/app/models/transaction/search.rb
@@ -102,10 +102,10 @@ class Transaction::Search
     def apply_category_filter(query, categories)
       return query unless categories.present?
 
-      # Remove "Uncategorized" from category names to query the database
-      uncategorized_name = Category.uncategorized.name
-      include_uncategorized = categories.include?(uncategorized_name)
-      real_categories = categories - [ uncategorized_name ]
+      # Check for "Uncategorized" in any supported locale (handles URL params in different languages)
+      all_uncategorized_names = Category.all_uncategorized_names
+      include_uncategorized = (categories & all_uncategorized_names).any?
+      real_categories = categories - all_uncategorized_names
 
       # Get parent category IDs for the given category names
       parent_category_ids = family.categories.where(name: real_categories).pluck(:id)
diff --git a/test/models/transaction/search_test.rb b/test/models/transaction/search_test.rb
index 164398d5a..c933c368c 100644
--- a/test/models/transaction/search_test.rb
+++ b/test/models/transaction/search_test.rb
@@ -494,4 +494,97 @@ class Transaction::SearchTest < ActiveSupport::TestCase
     # Should not match unrelated transactions
     assert_not_includes result_ids, no_match.entryable.id
   end
+
+  test "uncategorized filter returns same results across all supported locales" do
+    # Create uncategorized transactions
+    uncategorized1 = create_transaction(
+      account: @checking_account,
+      amount: 100,
+      kind: "standard"
+    )
+
+    uncategorized2 = create_transaction(
+      account: @checking_account,
+      amount: 200,
+      kind: "standard"
+    )
+
+    # Create a categorized transaction to ensure filter is working
+    categorized = create_transaction(
+      account: @checking_account,
+      amount: 300,
+      category: categories(:food_and_drink),
+      kind: "standard"
+    )
+
+    # Get the expected count using English locale (known working case)
+    I18n.with_locale(:en) do
+      english_uncategorized_name = Category.uncategorized.name
+      english_results = Transaction::Search.new(@family, filters: { categories: [ english_uncategorized_name ] }).transactions_scope
+      @expected_count = english_results.count
+      assert_equal 2, @expected_count, "English locale should return 2 uncategorized transactions"
+    end
+
+    # Test every supported locale returns the same count when filtering by that locale's uncategorized name
+    LanguagesHelper::SUPPORTED_LOCALES.each do |locale|
+      I18n.with_locale(locale) do
+        localized_uncategorized_name = Category.uncategorized.name
+        results = Transaction::Search.new(@family, filters: { categories: [ localized_uncategorized_name ] }).transactions_scope
+        result_count = results.count
+
+        assert_equal @expected_count, result_count,
+          "Locale '#{locale}' with uncategorized name '#{localized_uncategorized_name}' should return #{@expected_count} transactions but got #{result_count}"
+      end
+    end
+  end
+
+  test "uncategorized filter works with English parameter name regardless of current locale" do
+    # This tests the bug where URL contains English "Uncategorized" but user's locale is different
+    # Bug: /transactions/?q[categories][]=Uncategorized fails when locale is French
+
+    # Create uncategorized transactions
+    uncategorized1 = create_transaction(
+      account: @checking_account,
+      amount: 100,
+      kind: "standard"
+    )
+
+    uncategorized2 = create_transaction(
+      account: @checking_account,
+      amount: 200,
+      kind: "standard"
+    )
+
+    # Create a categorized transaction to ensure filter is working
+    categorized = create_transaction(
+      account: @checking_account,
+      amount: 300,
+      category: categories(:food_and_drink),
+      kind: "standard"
+    )
+
+    # Get the English uncategorized name (this is what URLs typically contain)
+    english_uncategorized_name = I18n.t("models.category.uncategorized", locale: :en)
+
+    # Get the expected count using English locale (known working case)
+    expected_count = nil
+    I18n.with_locale(:en) do
+      results = Transaction::Search.new(@family, filters: { categories: [ english_uncategorized_name ] }).transactions_scope
+      expected_count = results.count
+      assert_equal 2, expected_count, "English locale should return 2 uncategorized transactions"
+    end
+
+    # Test that using the English parameter name works in every supported locale
+    # This catches the bug where French locale fails with English "Uncategorized" parameter
+    LanguagesHelper::SUPPORTED_LOCALES.each do |locale|
+      I18n.with_locale(locale) do
+        # Simulate URL parameter: q[categories][]=Uncategorized (English, regardless of user's locale)
+        results = Transaction::Search.new(@family, filters: { categories: [ english_uncategorized_name ] }).transactions_scope
+        result_count = results.count
+
+        assert_equal expected_count, result_count,
+          "Locale '#{locale}' should return #{expected_count} transactions when filtering with English 'Uncategorized' parameter, but got #{result_count}"
+      end
+    end
+  end
 end