diff --git a/datacommons_client/endpoints/response.py b/datacommons_client/endpoints/response.py
index da78fc73..d10e6c9f 100644
--- a/datacommons_client/endpoints/response.py
+++ b/datacommons_client/endpoints/response.py
@@ -1,13 +1,16 @@
-from dataclasses import asdict, dataclass, field
+from dataclasses import asdict
+from dataclasses import dataclass
+from dataclasses import field
 from typing import Any, Dict, List
 
-from datacommons_client.models.node import Arcs, NextToken, NodeDCID, Properties
-from datacommons_client.models.observation import (
-    Facet,
-    Variable,
-    facetID,
-    variableDCID,
-)
+from datacommons_client.models.node import Arcs
+from datacommons_client.models.node import NextToken
+from datacommons_client.models.node import NodeDCID
+from datacommons_client.models.node import Properties
+from datacommons_client.models.observation import Facet
+from datacommons_client.models.observation import facetID
+from datacommons_client.models.observation import Variable
+from datacommons_client.models.observation import variableDCID
 from datacommons_client.models.resolve import Entity
 from datacommons_client.models.sparql import Row
 
diff --git a/datacommons_client/models/node.py b/datacommons_client/models/node.py
index cd964b87..5247ad32 100644
--- a/datacommons_client/models/node.py
+++ b/datacommons_client/models/node.py
@@ -1,4 +1,5 @@
-from dataclasses import dataclass, field
+from dataclasses import dataclass
+from dataclasses import field
 from typing import Any, Dict, List, Optional, TypeAlias
 
 NextToken: TypeAlias = Optional[str]
diff --git a/datacommons_client/models/observation.py b/datacommons_client/models/observation.py
index a0a86fd9..22819488 100644
--- a/datacommons_client/models/observation.py
+++ b/datacommons_client/models/observation.py
@@ -1,4 +1,5 @@
-from dataclasses import dataclass, field
+from dataclasses import dataclass
+from dataclasses import field
 from typing import Any, Dict, TypeAlias
 
 variableDCID: TypeAlias = str
diff --git a/datacommons_client/models/resolve.py b/datacommons_client/models/resolve.py
index 2b0ac665..6d20aacc 100644
--- a/datacommons_client/models/resolve.py
+++ b/datacommons_client/models/resolve.py
@@ -1,4 +1,5 @@
-from dataclasses import dataclass, field
+from dataclasses import dataclass
+from dataclasses import field
 from typing import Any, Dict, List, Optional, TypeAlias
 
 Query: TypeAlias = str
diff --git a/datacommons_client/models/sparql.py b/datacommons_client/models/sparql.py
index 1d8fd6ec..63e22b39 100644
--- a/datacommons_client/models/sparql.py
+++ b/datacommons_client/models/sparql.py
@@ -1,4 +1,5 @@
-from dataclasses import dataclass, field
+from dataclasses import dataclass
+from dataclasses import field
 from typing import Any, Dict, List
 
 
diff --git a/datacommons_client/tests/endpoints/test_response.py b/datacommons_client/tests/endpoints/test_response.py
index e71826fc..a30cc64b 100644
--- a/datacommons_client/tests/endpoints/test_response.py
+++ b/datacommons_client/tests/endpoints/test_response.py
@@ -1,19 +1,15 @@
-from datacommons_client.models.observation import (
-    Facet,
-    Observation,
-    OrderedFacets,
-    Variable,
-)
-from datacommons_client.endpoints.response import (
-    DCResponse,
-    NodeResponse,
-    ObservationResponse,
-    ResolveResponse,
-    SparqlResponse,
-    _unpack_arcs,
-    extract_observations,
-    flatten_properties,
-)
+from datacommons_client.endpoints.response import _unpack_arcs
+from datacommons_client.endpoints.response import DCResponse
+from datacommons_client.endpoints.response import extract_observations
+from datacommons_client.endpoints.response import flatten_properties
+from datacommons_client.endpoints.response import NodeResponse
+from datacommons_client.endpoints.response import ObservationResponse
+from datacommons_client.endpoints.response import ResolveResponse
+from datacommons_client.endpoints.response import SparqlResponse
+from datacommons_client.models.observation import Facet
+from datacommons_client.models.observation import Observation
+from datacommons_client.models.observation import OrderedFacets
+from datacommons_client.models.observation import Variable
 
 ### ----- Test DCResponse ----- ###
 
diff --git a/datacommons_client/tests/models/test_node_models.py b/datacommons_client/tests/models/test_node_models.py
index 9b65862f..40b6d85d 100644
--- a/datacommons_client/tests/models/test_node_models.py
+++ b/datacommons_client/tests/models/test_node_models.py
@@ -1,4 +1,7 @@
-from datacommons_client.models.node import Arcs, Node, NodeGroup, Properties
+from datacommons_client.models.node import Arcs
+from datacommons_client.models.node import Node
+from datacommons_client.models.node import NodeGroup
+from datacommons_client.models.node import Properties
 
 
 def test_node_from_json():
diff --git a/datacommons_client/tests/models/test_observation_models.py b/datacommons_client/tests/models/test_observation_models.py
index e25ca2c4..94535d2f 100644
--- a/datacommons_client/tests/models/test_observation_models.py
+++ b/datacommons_client/tests/models/test_observation_models.py
@@ -1,9 +1,7 @@
-from datacommons_client.models.observation import (
-    Facet,
-    Observation,
-    OrderedFacets,
-    Variable,
-)
+from datacommons_client.models.observation import Facet
+from datacommons_client.models.observation import Observation
+from datacommons_client.models.observation import OrderedFacets
+from datacommons_client.models.observation import Variable
 
 
 def test_observation_from_json():
diff --git a/datacommons_client/tests/models/test_resolve_models.py b/datacommons_client/tests/models/test_resolve_models.py
index 2887935a..44066781 100644
--- a/datacommons_client/tests/models/test_resolve_models.py
+++ b/datacommons_client/tests/models/test_resolve_models.py
@@ -1,4 +1,5 @@
-from datacommons_client.models.resolve import Candidate, Entity
+from datacommons_client.models.resolve import Candidate
+from datacommons_client.models.resolve import Entity
 
 
 def test_candidate_from_json():
diff --git a/datacommons_client/tests/models/test_sparql_models.py b/datacommons_client/tests/models/test_sparql_models.py
index 2f6e6a87..e9fa62a9 100644
--- a/datacommons_client/tests/models/test_sparql_models.py
+++ b/datacommons_client/tests/models/test_sparql_models.py
@@ -1,4 +1,5 @@
-from datacommons_client.models.sparql import Cell, Row
+from datacommons_client.models.sparql import Cell
+from datacommons_client.models.sparql import Row
 
 
 def test_cell_from_json():
diff --git a/datacommons_client/tests/utils/test_error_handling.py b/datacommons_client/tests/utils/test_error_handling.py
new file mode 100644
index 00000000..4ce234a4
--- /dev/null
+++ b/datacommons_client/tests/utils/test_error_handling.py
@@ -0,0 +1,68 @@
+from requests import Request
+from requests import Response
+
+from datacommons_client.utils.error_handling import APIError
+from datacommons_client.utils.error_handling import DataCommonsError
+from datacommons_client.utils.error_handling import DCAuthenticationError
+from datacommons_client.utils.error_handling import DCConnectionError
+from datacommons_client.utils.error_handling import DCStatusError
+from datacommons_client.utils.error_handling import InvalidDCInstanceError
+
+
+def test_data_commons_error_default_message():
+    """Tests that DataCommonsError uses the default message."""
+    error = DataCommonsError()
+    assert str(error) == DataCommonsError.default_message
+
+
+def test_data_commons_error_custom_message():
+    """Tests that DataCommonsError uses a custom message when provided."""
+    error = DataCommonsError("Custom message")
+    assert str(error) == "Custom message"
+
+
+def test_api_error_without_response():
+    """Tests APIError initialization without a Response object."""
+    error = APIError()
+    assert str(error) == f"\n{APIError.default_message}"
+
+
+def test_api_error_with_response():
+    """Tests APIError initialization with a mocked Response object.
+
+    Verifies that the string representation includes status code,
+    request URL, and response text.
+    """
+    mock_request = Request("GET", "http://example.com").prepare()
+    mock_response = Response()
+    mock_response.request = mock_request
+    mock_response.status_code = 404
+    mock_response._content = b"Not Found"
+
+    error = APIError(response=mock_response)
+    assert "Status Code: 404" in str(error)
+    assert "Request URL: http://example.com" in str(error)
+    assert "Not Found" in str(error)
+
+
+def test_subclass_default_messages():
+    """Tests that subclasses use their default messages."""
+    connection_error = DCConnectionError()
+    assert DCConnectionError.default_message in str(connection_error)
+
+    status_error = DCStatusError()
+    assert DCStatusError.default_message in str(status_error)
+
+    auth_error = DCAuthenticationError()
+    assert DCAuthenticationError.default_message in str(auth_error)
+
+    instance_error = InvalidDCInstanceError()
+    assert InvalidDCInstanceError.default_message in str(instance_error)
+
+
+def test_subclass_custom_message():
+    """Tests that subclasses use custom messages when provided."""
+    error = DCAuthenticationError(
+        response=Response(), message="Custom auth error"
+    )
+    assert str(error) == "\nCustom auth error"
diff --git a/datacommons_client/utils/error_handling.py b/datacommons_client/utils/error_handling.py
new file mode 100644
index 00000000..f7246716
--- /dev/null
+++ b/datacommons_client/utils/error_handling.py
@@ -0,0 +1,78 @@
+from typing import Optional
+
+from requests import Response
+
+
+class DataCommonsError(Exception):
+    """Base exception for all Data Commons-related errors."""
+
+    default_message = "An error occurred getting data from Data Commons API."
+
+    def __init__(self, message: Optional[str] = None):
+        """Initializes a DataCommonsError with a default or custom message."""
+        super().__init__(message or self.default_message)
+
+
+class APIError(DataCommonsError):
+    """Represents an error interacting with Data Commons API."""
+
+    default_message = "An API error occurred."
+
+    def __init__(
+        self,
+        response: Optional[Response] = None,
+        message: Optional[str] = None,
+    ):
+        """Initializes an APIError.
+
+        Args:
+            response (Optional[Response]): The response, if available.
+            message (Optional[str]): A descriptive error message.
+        """
+        super().__init__(message or self.default_message)
+        self.response = response
+        self.request = getattr(response, "request", None)
+        self.status_code = getattr(response, "status_code", None)
+
+    def __str__(self) -> str:
+        """Returns a detailed string representation of the error.
+
+        Returns:
+            str: A string describing the error, including the request URL if available.
+        """
+
+        details = f"\n{self.args[0]}"
+        if self.status_code:
+            details += f"\nStatus Code: {self.status_code}"
+        if getattr(self.request, "url", None):
+            details += f"\nRequest URL: {self.request.url}"
+        if getattr(self.response, "text", None):
+            details += f"\nResponse: {self.response.text}"
+
+        return details
+
+
+class DCConnectionError(APIError):
+    """Raised for network-related errors in the Data Commons API."""
+
+    default_message = (
+        "A network error occurred while connecting to the Data Commons API."
+    )
+
+
+class DCStatusError(APIError):
+    """Raised for non-2xx HTTP status code errors in the Data Commons API."""
+
+    default_message = "The Data Commons API returned a non-2xx status code."
+
+
+class DCAuthenticationError(APIError):
+    """Raised for 401 Unauthorized errors in the Data Commons API."""
+
+    default_message = "Authentication failed. Please check your API key."
+
+
+class InvalidDCInstanceError(DataCommonsError):
+    """Raised when an invalid Data Commons instance is provided."""
+
+    default_message = "The specified Data Commons instance is invalid."