diff --git a/README.md b/README.md
index 70c2bc3..16585c8 100644
--- a/README.md
+++ b/README.md
@@ -6,4 +6,4 @@
 - **string_utils** — String manipulation utilities: slugify, truncate, case conversion (snake_case, camelCase, PascalCase), and more.
 - **math_utils** — Math utilities: clamp, lerp, safe_divide, remap, and more.
 - **collection_utils** — Collection utilities: chunk, flatten, unique_by, group_by, partition, compact.
-- **constants** — Package-level constants (DEFAULT_HELLO_TARGET, DEFAULT_FAREWELL, DEFAULT_LANGUAGE).
+- **constants** — Package-level constants (DEFAULT_HELLO_TARGET, DEFAULT_FAREWELL, DEFAULT_LANGUAGE, DEFAULT_REGION).
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 436b586..a11cd75 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -2,6 +2,12 @@
 
 All notable changes to this project will be documented in this file.
 
+## [v007] - 2026-05-14
+
+### Added
+- `DEFAULT_REGION: str = "us"` constant to `constants` module (BL-022)
+- Test functions `test_default_region_value` and `test_default_region_type` in `test_constants.py`
+
 ## [v006] - 2026-05-14
 
 ### Added
diff --git a/src/test_target_2/constants.py b/src/test_target_2/constants.py
index c123c6f..e58b8bd 100644
--- a/src/test_target_2/constants.py
+++ b/src/test_target_2/constants.py
@@ -3,3 +3,4 @@
 DEFAULT_HELLO_TARGET: str = "world"
 DEFAULT_FAREWELL: str = "goodbye"
 DEFAULT_LANGUAGE: str = "en"
+DEFAULT_REGION: str = "us"
diff --git a/tests/test_constants.py b/tests/test_constants.py
index e4c229c..cd94294 100644
--- a/tests/test_constants.py
+++ b/tests/test_constants.py
@@ -35,3 +35,11 @@ def test_default_language_value() -> None:
 def test_default_language_type() -> None:
     """DEFAULT_LANGUAGE is string type."""
     assert isinstance(constants.DEFAULT_LANGUAGE, str)
+
+
+def test_default_region_value() -> None:
+    assert constants.DEFAULT_REGION == "us"
+
+
+def test_default_region_type() -> None:
+    assert isinstance(constants.DEFAULT_REGION, str)