diff --git a/sdk/identity/azure-identity/HISTORY.md b/sdk/identity/azure-identity/HISTORY.md
index f49fd18bd23f..2d7590e374b1 100644
--- a/sdk/identity/azure-identity/HISTORY.md
+++ b/sdk/identity/azure-identity/HISTORY.md
@@ -2,6 +2,10 @@
 
 ## 1.0.1
 
+- `ClientCertificateCredential` uses application and tenant IDs correctly
+([#8315](https://github.com/Azure/azure-sdk-for-python/pull/8315))
+
+
 ## 1.0.0 (2019-10-29)
 ### Breaking changes:
 - Async credentials now default to [`aiohttp`](https://pypi.org/project/aiohttp/)
diff --git a/sdk/identity/azure-identity/azure/identity/_authn_client.py b/sdk/identity/azure-identity/azure/identity/_authn_client.py
index 04b43a2b0618..e41994c29e3d 100644
--- a/sdk/identity/azure-identity/azure/identity/_authn_client.py
+++ b/sdk/identity/azure-identity/azure/identity/_authn_client.py
@@ -63,6 +63,10 @@ def __init__(self, endpoint=None, authority=None, tenant=None, **kwargs):  # pyl
             self._auth_url = "https://" + "/".join((authority.strip("/"), tenant.strip("/"), "oauth2/v2.0/token"))
         self._cache = kwargs.get("cache") or TokenCache()  # type: TokenCache
 
+    @property
+    def auth_url(self):
+        return self._auth_url
+
     def get_cached_token(self, scopes):
         # type: (Iterable[str]) -> Optional[AccessToken]
         tokens = self._cache.find(TokenCache.CredentialType.ACCESS_TOKEN, target=list(scopes))
diff --git a/sdk/identity/azure-identity/azure/identity/_base.py b/sdk/identity/azure-identity/azure/identity/_base.py
index 3bc20d84b3b5..98850e5f7231 100644
--- a/sdk/identity/azure-identity/azure/identity/_base.py
+++ b/sdk/identity/azure-identity/azure/identity/_base.py
@@ -2,14 +2,19 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 # ------------------------------------
+import abc
 import binascii
 
 from cryptography import x509
 from cryptography.hazmat.primitives import hashes, serialization
 from cryptography.hazmat.backends import default_backend
 from msal.oauth2cli import JwtSigner
+import six
 
-from ._constants import Endpoints
+try:
+    ABC = abc.ABC
+except AttributeError:  # Python 2.7, abc exists, but not ABC
+    ABC = abc.ABCMeta("ABC", (object,), {"__slots__": ()})  # type: ignore
 
 try:
     from typing import TYPE_CHECKING
@@ -38,7 +43,7 @@ def __init__(self, tenant_id, client_id, secret, **kwargs):  # pylint:disable=un
         super(ClientSecretCredentialBase, self).__init__()
 
 
-class CertificateCredentialBase(object):
+class CertificateCredentialBase(ABC):
     """Sans I/O base for certificate credentials"""
 
     def __init__(self, tenant_id, client_id, certificate_path, **kwargs):  # pylint:disable=unused-argument
@@ -58,16 +63,23 @@ def __init__(self, tenant_id, client_id, certificate_path, **kwargs):  # pylint:
         cert = x509.load_pem_x509_certificate(pem_bytes, default_backend())
         fingerprint = cert.fingerprint(hashes.SHA1())
 
-        self._auth_url = Endpoints.AAD_OAUTH2_V2_FORMAT.format(tenant_id)
+        self._client = self._get_auth_client(tenant_id, **kwargs)
         self._client_id = client_id
         self._signer = JwtSigner(private_key, "RS256", sha1_thumbprint=binascii.hexlify(fingerprint))
 
     def _get_request_data(self, *scopes):
-        assertion = self._signer.sign_assertion(audience=self._auth_url, issuer=self._client_id)
+        assertion = self._signer.sign_assertion(audience=self._client.auth_url, issuer=self._client_id)
+        if isinstance(assertion, six.binary_type):
+            assertion = assertion.decode("utf-8")
+
         return {
             "client_assertion": assertion,
             "client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
             "client_id": self._client_id,
             "grant_type": "client_credentials",
-            "scope": " ".join(scopes)
+            "scope": " ".join(scopes),
         }
+
+    @abc.abstractmethod
+    def _get_auth_client(self, tenant_id, **kwargs):
+        pass
diff --git a/sdk/identity/azure-identity/azure/identity/_credentials/client_credential.py b/sdk/identity/azure-identity/azure/identity/_credentials/client_credential.py
index 49cd6a2e92ca..10eae06c2b2a 100644
--- a/sdk/identity/azure-identity/azure/identity/_credentials/client_credential.py
+++ b/sdk/identity/azure-identity/azure/identity/_credentials/client_credential.py
@@ -63,11 +63,6 @@ class CertificateCredential(CertificateCredentialBase):
           defines authorities for other clouds.
     """
 
-    def __init__(self, tenant_id, client_id, certificate_path, **kwargs):
-        # type: (str, str, str, **Any) -> None
-        self._client = AuthnClient(tenant=tenant_id, **kwargs)
-        super(CertificateCredential, self).__init__(client_id, tenant_id, certificate_path, **kwargs)
-
     def get_token(self, *scopes, **kwargs):  # pylint:disable=unused-argument
         # type: (*str, **Any) -> AccessToken
         """Request an access token for `scopes`.
@@ -83,3 +78,6 @@ def get_token(self, *scopes, **kwargs):  # pylint:disable=unused-argument
             data = self._get_request_data(*scopes)
             token = self._client.request_token(scopes, form_data=data)
         return token
+
+    def _get_auth_client(self, tenant_id, **kwargs):
+        return AuthnClient(tenant=tenant_id, **kwargs)
diff --git a/sdk/identity/azure-identity/azure/identity/aio/_credentials/client_credential.py b/sdk/identity/azure-identity/azure/identity/aio/_credentials/client_credential.py
index 398035567fad..d674bee2ec8d 100644
--- a/sdk/identity/azure-identity/azure/identity/aio/_credentials/client_credential.py
+++ b/sdk/identity/azure-identity/azure/identity/aio/_credentials/client_credential.py
@@ -57,10 +57,6 @@ class CertificateCredential(CertificateCredentialBase):
           defines authorities for other clouds.
     """
 
-    def __init__(self, tenant_id: str, client_id: str, certificate_path: str, **kwargs: "Mapping[str, Any]") -> None:
-        super(CertificateCredential, self).__init__(tenant_id, client_id, certificate_path, **kwargs)
-        self._client = AsyncAuthnClient(tenant=tenant_id, **kwargs)
-
     async def get_token(self, *scopes: str, **kwargs: "Any") -> "AccessToken":  # pylint:disable=unused-argument
         """Asynchronously request an access token for `scopes`.
 
@@ -75,3 +71,6 @@ async def get_token(self, *scopes: str, **kwargs: "Any") -> "AccessToken":  # py
             data = self._get_request_data(*scopes)
             token = await self._client.request_token(scopes, form_data=data)
         return token  # type: ignore
+
+    def _get_auth_client(self, tenant_id, **kwargs):
+        return AsyncAuthnClient(tenant=tenant_id, **kwargs)
diff --git a/sdk/identity/azure-identity/tests/certificate.pem b/sdk/identity/azure-identity/tests/certificate.pem
new file mode 100644
index 000000000000..4b66bfa021a0
--- /dev/null
+++ b/sdk/identity/azure-identity/tests/certificate.pem
@@ -0,0 +1,49 @@
+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----
+-----BEGIN CERTIFICATE-----
+MIIDazCCAlOgAwIBAgIUF2VIP4+AnEtb52KTCHbo4+fESfswDQYJKoZIhvcNAQEL
+BQAwRTELMAkGA1UEBhMCQVUxEzARBgNVBAgMClNvbWUtU3RhdGUxITAfBgNVBAoM
+GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDAeFw0xOTEwMzAyMjQ2MjBaFw0yMjA4
+MTkyMjQ2MjBaMEUxCzAJBgNVBAYTAkFVMRMwEQYDVQQIDApTb21lLVN0YXRlMSEw
+HwYDVQQKDBhJbnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQwggEiMA0GCSqGSIb3DQEB
+AQUAA4IBDwAwggEKAoIBAQDL1hG+JYCfIPp3tlZ05J4pYIJ3Ckfs432bE3rYuWlR
+2w9KqdjWkKxuAxpjJ+T+uoqVaT3BFMfi4ZRYOCI69s4+lP3DwR8uBCp9xyVkF8th
+XfS3iui0liGDviVBoBJJWvjDFU8a/Hseg+QfoxAb6tx0kEc7V3ozBLWoIDJjfwJ3
+NdsLZGVtAC34qCWeEIvS97CDA4g3Kc6hYJIrAa7pxHzo/Nd0U3e7z+DlBcJV7dY6
+TZUyjBVTpzppWe+XQEOfKsjkDNykHEC1C1bClG0u7unS7QOBMd6bOGkeL+Bc+n22
+slTzs5amsbDLNuobSaUsFt9vgD5jRD6FwhpXwj/Ek0F7AgMBAAGjUzBRMB0GA1Ud
+DgQWBBT6Mf9uXFB67bY2PeW3GCTKfkO7vDAfBgNVHSMEGDAWgBT6Mf9uXFB67bY2
+PeW3GCTKfkO7vDAPBgNVHRMBAf8EBTADAQH/MA0GCSqGSIb3DQEBCwUAA4IBAQCZ
+1+kTISX85v9/ag7glavaPFUYsOSOOofl8gSzov7L01YL+srq7tXdvZmWrjQ/dnOY
+h18rp9rb24vwIYxNioNG/M2cW1jBJwEGsDPOwdPV1VPcRmmUJW9kY130gRHBCd/N
+qB7dIkcQnpNsxPIIWI+sRQp73U0ijhOByDnCNHLHon6vbfFTwkO1XggmV5BdZ3uQ
+JNJyckILyNzlhmf6zhonMp4lVzkgxWsAm2vgdawd6dmBa+7Avb2QK9s+IdUSutFh
+DgW2L12Obgh12Y4sf1iKQXA0RbZ2k+XQIz8EKZa7vJQY0ciYXSgB/BV3a96xX3cx
+LIPL8Vam8Ytkopi3gsGA
+-----END CERTIFICATE-----
\ No newline at end of file
diff --git a/sdk/identity/azure-identity/tests/helpers.py b/sdk/identity/azure-identity/tests/helpers.py
index 694a92df922a..85eb7ff95cb2 100644
--- a/sdk/identity/azure-identity/tests/helpers.py
+++ b/sdk/identity/azure-identity/tests/helpers.py
@@ -2,7 +2,9 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
 # ------------------------------------
+import base64
 import json
+import six
 
 try:
     from unittest import mock
@@ -60,6 +62,14 @@ def validate_request(request, **kwargs):
     return mock.Mock(send=validate_request)
 
 
+def urlsafeb64_decode(s):
+    if isinstance(s, six.text_type):
+        s = s.encode("ascii")
+
+    padding_needed = 4 - len(s) % 4
+    return base64.urlsafe_b64decode(s + b"=" * padding_needed)
+
+
 try:
     import asyncio
 
diff --git a/sdk/identity/azure-identity/tests/test_certificate_credential.py b/sdk/identity/azure-identity/tests/test_certificate_credential.py
new file mode 100644
index 000000000000..7cf4c8e698bb
--- /dev/null
+++ b/sdk/identity/azure-identity/tests/test_certificate_credential.py
@@ -0,0 +1,60 @@
+# ------------------------------------
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+# ------------------------------------
+import json
+import os
+
+from azure.identity import CertificateCredential
+from six.moves.urllib_parse import urlparse
+from helpers import urlsafeb64_decode, mock_response
+
+try:
+    from unittest.mock import Mock, patch
+except ImportError:  # python < 3.3
+    from mock import Mock, patch  # type: ignore
+
+CERT_PATH = os.path.join(os.path.dirname(__file__), "certificate.pem")
+
+
+def test_request_url():
+    authority = "authority.com"
+    tenant_id = "expected_tenant"
+    access_token = "***"
+
+    def validate_url(url):
+        scheme, netloc, path, _, _, _ = urlparse(url)
+        assert scheme == "https"
+        assert netloc == authority
+        assert path.startswith("/" + tenant_id)
+
+    def mock_send(request, **kwargs):
+        validate_url(request.url)
+        return mock_response(json_payload={"token_type": "Bearer", "expires_in": 42, "access_token": access_token})
+
+    cred = CertificateCredential(tenant_id, "client_id", CERT_PATH, transport=Mock(send=mock_send), authority=authority)
+    token = cred.get_token("scope")
+    assert token.token == access_token
+
+
+def test_request_body():
+    access_token = "***"
+    authority = "authority.com"
+    tenant_id = "tenant"
+
+    def validate_url(url):
+        scheme, netloc, path, _, _, _ = urlparse(url)
+        assert scheme == "https"
+        assert netloc == authority
+        assert path.startswith("/" + tenant_id)
+
+    def mock_send(request, **kwargs):
+        jwt = request.body["client_assertion"]
+        header, payload, signature = (urlsafeb64_decode(s) for s in jwt.split("."))
+        claims = json.loads(payload.decode("utf-8"))
+        validate_url(claims["aud"])
+        return mock_response(json_payload={"token_type": "Bearer", "expires_in": 42, "access_token": access_token})
+
+    cred = CertificateCredential(tenant_id, "client_id", CERT_PATH, transport=Mock(send=mock_send), authority=authority)
+    token = cred.get_token("scope")
+    assert token.token == access_token
diff --git a/sdk/identity/azure-identity/tests/test_certificate_credential_async.py b/sdk/identity/azure-identity/tests/test_certificate_credential_async.py
new file mode 100644
index 000000000000..3ef0b71da665
--- /dev/null
+++ b/sdk/identity/azure-identity/tests/test_certificate_credential_async.py
@@ -0,0 +1,59 @@
+# ------------------------------------
+# Copyright (c) Microsoft Corporation.
+# Licensed under the MIT License.
+# ------------------------------------
+import json
+import os
+from unittest.mock import Mock, patch
+from urllib.parse import urlparse
+
+from azure.identity.aio import CertificateCredential
+from helpers import urlsafeb64_decode, mock_response
+import pytest
+
+CERT_PATH = os.path.join(os.path.dirname(__file__), "certificate.pem")
+
+
+@pytest.mark.asyncio
+async def test_request_url():
+    authority = "authority.com"
+    tenant_id = "expected_tenant"
+    access_token = "***"
+
+    def validate_url(url):
+        scheme, netloc, path, _, _, _ = urlparse(url)
+        assert scheme == "https"
+        assert netloc == authority
+        assert path.startswith("/" + tenant_id)
+
+    async def mock_send(request, **kwargs):
+        validate_url(request.url)
+        return mock_response(json_payload={"token_type": "Bearer", "expires_in": 42, "access_token": access_token})
+
+    cred = CertificateCredential(tenant_id, "client_id", CERT_PATH, transport=Mock(send=mock_send), authority=authority)
+    token = await cred.get_token("scope")
+    assert token.token == access_token
+
+
+@pytest.mark.asyncio
+async def test_request_body():
+    access_token = "***"
+    authority = "authority.com"
+    tenant_id = "tenant"
+
+    def validate_url(url):
+        scheme, netloc, path, _, _, _ = urlparse(url)
+        assert scheme == "https"
+        assert netloc == authority
+        assert path.startswith("/" + tenant_id)
+
+    async def mock_send(request, **kwargs):
+        jwt = request.body["client_assertion"]
+        header, payload, signature = (urlsafeb64_decode(s) for s in jwt.split("."))
+        claims = json.loads(payload.decode("utf-8"))
+        validate_url(claims["aud"])
+        return mock_response(json_payload={"token_type": "Bearer", "expires_in": 42, "access_token": access_token})
+
+    cred = CertificateCredential(tenant_id, "client_id", CERT_PATH, transport=Mock(send=mock_send), authority=authority)
+    token = await cred.get_token("scope")
+    assert token.token == access_token