diff --git a/qiskit/__init__.py b/qiskit/__init__.py
index 20f2e3c80851..8075ae39d3c9 100644
--- a/qiskit/__init__.py
+++ b/qiskit/__init__.py
@@ -14,7 +14,6 @@
 
 """Main Qiskit public functionality."""
 
-import pkgutil
 import sys
 import warnings
 
@@ -69,14 +68,6 @@
 import qiskit.circuit.measure
 import qiskit.circuit.reset
 
-# Allow extending this namespace. Please note that currently this line needs
-# to be placed *before* the wrapper imports or any non-import code AND *before*
-# importing the package you want to allow extensions for (in this case `backends`).
-
-# Support for the deprecated extending this namespace.
-# Remove this after 0.46.0 release
-__path__ = pkgutil.extend_path(__path__, __name__)
-
 # Please note these are global instances, not modules.
 from qiskit.providers.basicaer import BasicAer
 
diff --git a/qiskit/providers/__init__.py b/qiskit/providers/__init__.py
index d7ec4b21b9fe..0c3da6d21197 100644
--- a/qiskit/providers/__init__.py
+++ b/qiskit/providers/__init__.py
@@ -750,8 +750,6 @@ def status(self):
 to wrap a :class:`~.BackendV1` object with a :class:`~.BackendV2` interface.
 """
 
-import pkgutil
-
 # Providers interface
 from qiskit.providers.provider import Provider
 from qiskit.providers.provider import ProviderV1
@@ -773,8 +771,3 @@ def status(self):
     BackendConfigurationError,
 )
 from qiskit.providers.jobstatus import JobStatus
-
-
-# Support for the deprecated extending this namespace.
-# Remove this after 0.46.0 release
-__path__ = pkgutil.extend_path(__path__, __name__)
diff --git a/releasenotes/notes/remove-namespace-hooks-995bdb7515a9fe35.yaml b/releasenotes/notes/remove-namespace-hooks-995bdb7515a9fe35.yaml
new file mode 100644
index 000000000000..df8601ba031c
--- /dev/null
+++ b/releasenotes/notes/remove-namespace-hooks-995bdb7515a9fe35.yaml
@@ -0,0 +1,14 @@
+---
+upgrade:
+  - |
+    Support for extensions of the ``qiskit`` and ``qiskit.providers`` namespaces
+    by external packages has been removed. Support for doing this was deprecated
+    in the Qiskit 0.44.0 release. In the past, the Qiskit project was composed
+    of elements that extended a shared namespace and hook points were added
+    to enable doing that. However, it was not intended for these interfaces to
+    ever be used by other packages. Now that the overall Qiskit package is no
+    longer using that packaging model, leaving the possibility for these
+    extensions carry more risk than benefits and has therefore been removed.
+    If you’re maintaining a package that extends the Qiskit namespace (i.e.
+    your users import from ``qiskit.x`` or ``qiskit.providers.y``) you should
+    transition to using a standalone Python namespace for your package.