diff --git a/changelog/14488.bugfix.rst b/changelog/14488.bugfix.rst
new file mode 100644
index 00000000000..b54324ae9e3
--- /dev/null
+++ b/changelog/14488.bugfix.rst
@@ -0,0 +1 @@
+Raise a descriptive :class:`RuntimeError` instead of a :class:`KeyError` when accessing ``caplog.handler`` before it has been initialized.
diff --git a/src/_pytest/logging.py b/src/_pytest/logging.py
index 2a22c9eb4aa..d138f8600dd 100644
--- a/src/_pytest/logging.py
+++ b/src/_pytest/logging.py
@@ -449,7 +449,10 @@ def _finalize(self) -> None:
     @property
     def handler(self) -> LogCaptureHandler:
         """Get the logging handler used by the fixture."""
-        return self._item.stash[caplog_handler_key]
+        handler = self._item.stash.get(caplog_handler_key, None)
+        if handler is None:
+            raise RuntimeError("caplog handler was not initialized for this test item")
+        return handler
 
     def get_records(
         self, when: Literal["setup", "call", "teardown"]
diff --git a/testing/logging/test_fixture.py b/testing/logging/test_fixture.py
index c98b7d84258..b8e29f053d2 100644
--- a/testing/logging/test_fixture.py
+++ b/testing/logging/test_fixture.py
@@ -5,6 +5,7 @@
 from collections.abc import Iterator
 import logging
 
+from _pytest.logging import caplog_handler_key
 from _pytest.logging import caplog_records_key
 from _pytest.pytester import Pytester
 import pytest
@@ -508,3 +509,10 @@ def test_that_fails(request, caplog):
         ["*Print message*", "*INFO log message*", "*WARNING log message*"]
     )
     assert result.ret == 1
+
+
+def test_caplog_missing_handler_raises_error(caplog: pytest.LogCaptureFixture) -> None:
+    del caplog._item.stash[caplog_handler_key]
+
+    with pytest.raises(RuntimeError, match="caplog handler was not initialized"):
+        _ = caplog.handler