diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8e3f480c8..4462ff604 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # HDMF Changelog
 
+## [Unreleased]
+
+### Changed
+- `hdmf.monitor` is unused and undocumented. It has been deprecated and will be removed in HDMF 5.0. @rly [#1245](https://github.com/hdmf-dev/hdmf/pull/1245)
+
 ## HDMF 4.0.0 (January 22, 2025)
 
 ### Breaking changes
diff --git a/src/hdmf/monitor.py b/src/hdmf/monitor.py
index 823ccf72d..9f8e7e0cc 100644
--- a/src/hdmf/monitor.py
+++ b/src/hdmf/monitor.py
@@ -1,8 +1,16 @@
 from abc import ABCMeta, abstractmethod
+import warnings
 
 from .data_utils import AbstractDataChunkIterator, DataChunkIterator, DataChunk
 from .utils import docval, getargs
 
+warnings.warn(
+    "The hdmf.monitor module is deprecated and will be removed in HDMF 5.0. If you are using this module, "
+    "please copy this module to your codebase or raise an issue in the HDMF repository: "
+    "https://github.com/hdmf-dev/hdmf/issues",
+    DeprecationWarning,
+)
+
 
 class NotYetExhausted(Exception):
     pass
diff --git a/tests/unit/test_monitor.py b/tests/unit/test_monitor.py
new file mode 100644
index 000000000..f9af06a9c
--- /dev/null
+++ b/tests/unit/test_monitor.py
@@ -0,0 +1,6 @@
+import pytest
+
+
+def test_deprecation_warning():
+    with pytest.warns(DeprecationWarning):
+        import hdmf.monitor  # noqa: F401