diff --git a/src/glean/api_client/_hooks/registration.py b/src/glean/api_client/_hooks/registration.py
index a064445e..8d8610f1 100644
--- a/src/glean/api_client/_hooks/registration.py
+++ b/src/glean/api_client/_hooks/registration.py
@@ -1,4 +1,5 @@
 from .types import Hooks
+from .server_url_normalizer import ServerURLNormalizerHook
 from .multipart_fix_hook import MultipartFileFieldFixHook
 from .agent_file_upload_error_hook import AgentFileUploadErrorHook
 from .x_glean import XGlean
@@ -15,6 +16,9 @@ def init_hooks(hooks: Hooks):
     with an instance of a hook that implements that specific Hook interface
     Hooks are registered per SDK instance, and are valid for the lifetime of the SDK instance"""
 
+    # Register hook to normalize server URLs (prepend https:// if no scheme provided)
+    hooks.register_sdk_init_hook(ServerURLNormalizerHook())
+
     # Register hook to fix multipart file field names that incorrectly have '[]' suffix
     hooks.register_sdk_init_hook(MultipartFileFieldFixHook())
 
diff --git a/src/glean/api_client/_hooks/server_url_normalizer.py b/src/glean/api_client/_hooks/server_url_normalizer.py
new file mode 100644
index 00000000..42561988
--- /dev/null
+++ b/src/glean/api_client/_hooks/server_url_normalizer.py
@@ -0,0 +1,21 @@
+"""Hook to normalize server URLs, prepending https:// if no scheme is provided."""
+
+import re
+from typing import Tuple
+from .types import SDKInitHook
+from glean.api_client.httpclient import HttpClient
+
+
+def normalize_server_url(url: str) -> str:
+    normalized = url
+    if not re.match(r'^https?://', normalized, re.IGNORECASE):
+        normalized = f'https://{normalized}'
+    normalized = normalized.rstrip('/')
+    return normalized
+
+
+class ServerURLNormalizerHook(SDKInitHook):
+    """Normalizes server URLs by prepending https:// if no scheme is provided."""
+
+    def sdk_init(self, base_url: str, client: HttpClient) -> Tuple[str, HttpClient]:
+        return normalize_server_url(base_url), client
diff --git a/tests/test_server_url_normalizer.py b/tests/test_server_url_normalizer.py
new file mode 100644
index 00000000..ef9f8696
--- /dev/null
+++ b/tests/test_server_url_normalizer.py
@@ -0,0 +1,71 @@
+"""Tests for the server URL normalizer hook."""
+
+from unittest.mock import Mock
+
+import pytest
+
+from src.glean.api_client._hooks.server_url_normalizer import (
+    ServerURLNormalizerHook,
+    normalize_server_url,
+)
+from src.glean.api_client.httpclient import HttpClient
+
+
+class TestNormalizeServerUrl:
+    """Test cases for the normalize_server_url function."""
+
+    def test_no_scheme_prepends_https(self):
+        assert normalize_server_url("example.glean.com") == "https://example.glean.com"
+
+    def test_https_preserved(self):
+        assert normalize_server_url("https://example.glean.com") == "https://example.glean.com"
+
+    def test_http_localhost_preserved(self):
+        assert normalize_server_url("http://localhost:8080") == "http://localhost:8080"
+
+    def test_http_non_localhost_preserved(self):
+        assert normalize_server_url("http://example.glean.com") == "http://example.glean.com"
+
+    def test_trailing_slash_stripped(self):
+        assert normalize_server_url("https://example.glean.com/") == "https://example.glean.com"
+
+    def test_multiple_trailing_slashes_stripped(self):
+        assert normalize_server_url("https://example.glean.com///") == "https://example.glean.com"
+
+    def test_no_scheme_with_trailing_slash(self):
+        assert normalize_server_url("example.glean.com/") == "https://example.glean.com"
+
+    def test_url_with_path(self):
+        assert normalize_server_url("https://example.glean.com/api/v1") == "https://example.glean.com/api/v1"
+
+    def test_url_with_path_and_trailing_slash(self):
+        assert normalize_server_url("https://example.glean.com/api/v1/") == "https://example.glean.com/api/v1"
+
+    def test_no_scheme_with_path(self):
+        assert normalize_server_url("example.glean.com/api/v1") == "https://example.glean.com/api/v1"
+
+    def test_case_insensitive_scheme(self):
+        assert normalize_server_url("HTTPS://example.glean.com") == "HTTPS://example.glean.com"
+        assert normalize_server_url("HTTP://localhost") == "HTTP://localhost"
+
+
+class TestServerURLNormalizerHook:
+    """Test cases for the ServerURLNormalizerHook."""
+
+    def setup_method(self):
+        self.hook = ServerURLNormalizerHook()
+        self.mock_client = Mock(spec=HttpClient)
+
+    def test_sdk_init_normalizes_url(self):
+        result_url, result_client = self.hook.sdk_init("example.glean.com", self.mock_client)
+        assert result_url == "https://example.glean.com"
+        assert result_client == self.mock_client
+
+    def test_sdk_init_preserves_client(self):
+        result_url, result_client = self.hook.sdk_init("https://example.glean.com", self.mock_client)
+        assert result_url == "https://example.glean.com"
+        assert result_client is self.mock_client
+
+
+if __name__ == "__main__":
+    pytest.main([__file__])