diff --git a/litellm/containers/endpoint_factory.py b/litellm/containers/endpoint_factory.py
index 25fc223cde0..a6727b7ce49 100644
--- a/litellm/containers/endpoint_factory.py
+++ b/litellm/containers/endpoint_factory.py
@@ -38,7 +38,7 @@ RESPONSE_TYPES: Final[dict[str, type]] = {
 def _load_endpoints_config() -> dict:
     """Load the endpoints configuration from JSON file."""
     config_path: Final = Path(__file__).parent / "endpoints.json"
-    with open(config_path) as f:
+    with open(config_path, encoding="utf-8") as f:
         return json.load(f)
 
 
diff --git a/litellm/proxy/_lazy_openapi_snapshot.py b/litellm/proxy/_lazy_openapi_snapshot.py
index 92578aa43b9..9f70964267b 100644
--- a/litellm/proxy/_lazy_openapi_snapshot.py
+++ b/litellm/proxy/_lazy_openapi_snapshot.py
@@ -55,7 +55,7 @@ def load_snapshot() -> dict[str, dict] | None:
     if not SNAPSHOT_FILE.exists():
         return None
     try:
-        with SNAPSHOT_FILE.open() as f:
+        with SNAPSHOT_FILE.open(encoding="utf-8") as f:
             return json.load(f)
     except (json.JSONDecodeError, OSError):
         return None
diff --git a/litellm/proxy/container_endpoints/handler_factory.py b/litellm/proxy/container_endpoints/handler_factory.py
index 3989bdacef1..837432c0abe 100644
--- a/litellm/proxy/container_endpoints/handler_factory.py
+++ b/litellm/proxy/container_endpoints/handler_factory.py
@@ -30,7 +30,7 @@ from litellm.proxy.container_endpoints.ownership import (
 def _load_endpoints_config() -> dict:
     """Load the endpoints configuration from JSON file."""
     config_path: Final = Path(__file__).parent.parent.parent / "containers" / "endpoints.json"
-    with open(config_path) as f:
+    with open(config_path, encoding="utf-8") as f:
         return json.load(f)
 
 
diff --git a/litellm/proxy/proxy_server.py b/litellm/proxy/proxy_server.py
index a994293a4d8..66487fd89bd 100644
--- a/litellm/proxy/proxy_server.py
+++ b/litellm/proxy/proxy_server.py
@@ -5390,7 +5390,7 @@ class ProxyConfig:
         Load and parse a YAML file
         """
         try:
-            with open(file_path, "r") as file:
+            with open(file_path, "r", encoding="utf-8") as file:
                 return yaml.safe_load(file) or {}
         except Exception as e:
             raise Exception(f"Error loading yaml file {file_path}: {e}")
@@ -5411,7 +5411,7 @@ class ProxyConfig:
         # Load existing config
         ## Yaml
         if os.path.exists(f"{file_path}"):
-            with open(f"{file_path}", "r") as config_file:
+            with open(f"{file_path}", "r", encoding="utf-8") as config_file:
                 config = yaml.safe_load(config_file)
         elif file_path is not None:
             raise Exception(f"Config file not found: {file_path}")
diff --git a/tests/test_litellm/proxy/test_proxy_server.py b/tests/test_litellm/proxy/test_proxy_server.py
index 23d319159ca..11f62fb3400 100644
--- a/tests/test_litellm/proxy/test_proxy_server.py
+++ b/tests/test_litellm/proxy/test_proxy_server.py
@@ -14211,6 +14211,63 @@ async def test_ptu_rollup_job_not_registered_without_opt_in(monkeypatch):
     assert len(scheduler.get_jobs()) > 0
 
 
+CONFIG_WITH_NON_ASCII = """model_list:
+  - model_name: café-gpt
+    litellm_params:
+      model: openai/gpt-4o
+      api_key: sk-test
+"""
+
+
+def test_load_yaml_file_reads_non_ascii_config(tmp_path):
+    """A UTF-8 config decoded with the locale encoding silently yields café-gpt on a cp1252 host,
+    so the wrong model name reaches routing with no error raised."""
+    from litellm.proxy.proxy_server import ProxyConfig
+
+    config_path = tmp_path / "config.yaml"
+    config_path.write_text(CONFIG_WITH_NON_ASCII, encoding="utf-8")
+
+    config = ProxyConfig()._load_yaml_file(str(config_path))
+
+    assert config["model_list"][0]["model_name"] == "café-gpt"
+
+
+def test_load_yaml_file_reads_config_with_byte_undefined_in_cp1252(tmp_path):
+    """Cafe plus U+0301 encodes to a 0x81 byte, which cp1252 has no mapping for, so this raised
+    UnicodeDecodeError rather than merely mangling the name."""
+    from litellm.proxy.proxy_server import ProxyConfig
+
+    config_path = tmp_path / "config.yaml"
+    config_path.write_text("model_list:\n  - model_name: Café\n", encoding="utf-8")
+
+    config = ProxyConfig()._load_yaml_file(str(config_path))
+
+    assert config["model_list"][0]["model_name"] == "Café"
+
+
+def test_load_yaml_file_specifies_an_encoding(tmp_path):
+    """Asserting the decoded value passes on any UTF-8 host regardless of the fix, and CI is Linux.
+    Running the loader under warn_default_encoding fails on every platform instead."""
+    config_path = tmp_path / "config.yaml"
+    config_path.write_text(CONFIG_WITH_NON_ASCII, encoding="utf-8")
+
+    body = (
+        "import warnings\n"
+        "from litellm.proxy.proxy_server import ProxyConfig\n"
+        'warnings.simplefilter("error", EncodingWarning)\n'
+        f'config = ProxyConfig()._load_yaml_file(r"{config_path}")\n'
+        'assert config["model_list"][0]["model_name"] == "caf\u00e9-gpt", config\n'
+        'print("OK")\n'
+    )
+    proc = subprocess.run(
+        [sys.executable, "-X", "warn_default_encoding", "-W", "error::EncodingWarning", "-c", body],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+
+    assert "EncodingWarning" not in proc.stderr, proc.stderr
+    assert proc.returncode == 0, proc.stderr
 @pytest.mark.asyncio
 async def test_moderations_reraises_proxy_exception_unwrapped():
     """A 400 ProxyException from request validation must surface as-is,