diff --git a/changelog/9396.bugfix.rst b/changelog/9396.bugfix.rst
new file mode 100644
index 000000000..dcb83bbc1
--- /dev/null
+++ b/changelog/9396.bugfix.rst
@@ -0,0 +1 @@
+Ensure :attr:`pytest.Config.inifile` is available during the :func:`pytest_cmdline_main <_pytest.hookspec.pytest_cmdline_main>` hook (regression during ``7.0.0rc1``).
diff --git a/src/_pytest/legacypath.py b/src/_pytest/legacypath.py
index 4c2db9412..37e8c2422 100644
--- a/src/_pytest/legacypath.py
+++ b/src/_pytest/legacypath.py
@@ -403,14 +403,44 @@ def Node_fspath_set(self: Node, value: LEGACY_PATH) -> None:
     self.path = Path(value)
 
 
+@hookimpl(tryfirst=True)
+def pytest_load_initial_conftests(early_config: Config) -> None:
+    """Monkeypatch legacy path attributes in several classes, as early as possible."""
+    mp = MonkeyPatch()
+    early_config.add_cleanup(mp.undo)
+
+    # Add Cache.makedir().
+    mp.setattr(Cache, "makedir", Cache_makedir, raising=False)
+
+    # Add FixtureRequest.fspath property.
+    mp.setattr(FixtureRequest, "fspath", property(FixtureRequest_fspath), raising=False)
+
+    # Add TerminalReporter.startdir property.
+    mp.setattr(
+        TerminalReporter, "startdir", property(TerminalReporter_startdir), raising=False
+    )
+
+    # Add Config.{invocation_dir,rootdir,inifile} properties.
+    mp.setattr(Config, "invocation_dir", property(Config_invocation_dir), raising=False)
+    mp.setattr(Config, "rootdir", property(Config_rootdir), raising=False)
+    mp.setattr(Config, "inifile", property(Config_inifile), raising=False)
+
+    # Add Session.startdir property.
+    mp.setattr(Session, "startdir", property(Session_stardir), raising=False)
+
+    # Add pathlist configuration type.
+    mp.setattr(Config, "_getini_unknown_type", Config__getini_unknown_type)
+
+    # Add Node.fspath property.
+    mp.setattr(Node, "fspath", property(Node_fspath, Node_fspath_set), raising=False)
+
+
 @hookimpl
 def pytest_configure(config: Config) -> None:
-    import pytest
-
-    mp = pytest.MonkeyPatch()
-    config.add_cleanup(mp.undo)
-
+    """Installs the LegacyTmpdirPlugin if the ``tmpdir`` plugin is also installed."""
     if config.pluginmanager.has_plugin("tmpdir"):
+        mp = MonkeyPatch()
+        config.add_cleanup(mp.undo)
         # Create TmpdirFactory and attach it to the config object.
         #
         # This is to comply with existing plugins which expect the handler to be
@@ -427,35 +457,6 @@ def pytest_configure(config: Config) -> None:
 
         config.pluginmanager.register(LegacyTmpdirPlugin, "legacypath-tmpdir")
 
-    # Add Cache.makedir().
-    mp.setattr(pytest.Cache, "makedir", Cache_makedir, raising=False)
-
-    # Add FixtureRequest.fspath property.
-    mp.setattr(
-        pytest.FixtureRequest, "fspath", property(FixtureRequest_fspath), raising=False
-    )
-
-    # Add TerminalReporter.startdir property.
-    mp.setattr(
-        TerminalReporter, "startdir", property(TerminalReporter_startdir), raising=False
-    )
-
-    # Add Config.{invocation_dir,rootdir,inifile} properties.
-    mp.setattr(
-        pytest.Config, "invocation_dir", property(Config_invocation_dir), raising=False
-    )
-    mp.setattr(pytest.Config, "rootdir", property(Config_rootdir), raising=False)
-    mp.setattr(pytest.Config, "inifile", property(Config_inifile), raising=False)
-
-    # Add Session.startdir property.
-    mp.setattr(pytest.Session, "startdir", property(Session_stardir), raising=False)
-
-    # Add pathlist configuration type.
-    mp.setattr(pytest.Config, "_getini_unknown_type", Config__getini_unknown_type)
-
-    # Add Node.fspath property.
-    mp.setattr(Node, "fspath", property(Node_fspath, Node_fspath_set), raising=False)
-
 
 @hookimpl
 def pytest_plugin_registered(plugin: object, manager: PytestPluginManager) -> None:
diff --git a/testing/test_config.py b/testing/test_config.py
index 9a57b919d..f691d3ed5 100644
--- a/testing/test_config.py
+++ b/testing/test_config.py
@@ -1268,6 +1268,7 @@ def test_load_initial_conftest_last_ordering(_config_for_test):
     expected = [
         "_pytest.config",
         m.__module__,
+        "_pytest.legacypath",
         "_pytest.pythonpath",
         "_pytest.capture",
         "_pytest.warnings",
diff --git a/testing/test_legacypath.py b/testing/test_legacypath.py
index 1d3fdb4bd..fbfd88b73 100644
--- a/testing/test_legacypath.py
+++ b/testing/test_legacypath.py
@@ -161,3 +161,20 @@ def test_override_ini_paths(pytester: pytest.Pytester) -> None:
     )
     result = pytester.runpytest("--override-ini", "paths=foo/bar1.py foo/bar2.py", "-s")
     result.stdout.fnmatch_lines(["user_path:bar1.py", "user_path:bar2.py"])
+
+
+def test_inifile_from_cmdline_main_hook(pytester: pytest.Pytester) -> None:
+    """Ensure Config.inifile is available during pytest_cmdline_main (#9396)."""
+    p = pytester.makeini(
+        """
+        [pytest]
+        """
+    )
+    pytester.makeconftest(
+        """
+        def pytest_cmdline_main(config):
+            print("pytest_cmdline_main inifile =", config.inifile)
+        """
+    )
+    result = pytester.runpytest_subprocess("-s")
+    result.stdout.fnmatch_lines(f"*pytest_cmdline_main inifile = {p}")