diff --git a/doc/changes/dev/13963.bugfix.rst b/doc/changes/dev/13963.bugfix.rst
new file mode 100644
index 00000000000..c273e4e7206
--- /dev/null
+++ b/doc/changes/dev/13963.bugfix.rst
@@ -0,0 +1 @@
+Fixed bug where :func:`mne.sys_info` would silently change the active Matplotlib backend (e.g. when ``ipympl`` is installed) as an import-time side effect, by `Stefan Appelhoff`_.
diff --git a/mne/utils/config.py b/mne/utils/config.py
index ff7ec4f6285..0794f0b7276 100644
--- a/mne/utils/config.py
+++ b/mne/utils/config.py
@@ -880,6 +880,15 @@ def sys_info(
         unicode = False
     mne_version_good = True
     import_names = dict(hedtools="hed")
+    # ``import_module`` below imports each optional dependency purely to read its
+    # version. Some packages change global state at import time -- most notably
+    # ``ipympl``, which switches the Matplotlib backend. Snapshot the backend so
+    # that merely calling ``sys_info`` does not mutate the caller's backend.
+    mpl_backend = None
+    with contextlib.suppress(Exception):
+        import matplotlib
+
+        mpl_backend = matplotlib.get_backend()
     for mi, mod_name in enumerate(use_mod_names):
         # upcoming break
         if mod_name == "":  # break
@@ -955,6 +964,15 @@ def sys_info(
                 out(f"\n{pre}{' ' * ljust}{op.dirname(mod.__file__)}")
             out("\n")
 
+    # Restore the Matplotlib backend in case importing a dependency above
+    # (e.g. ipympl) changed it as an import-time side effect.
+    if mpl_backend is not None:
+        with contextlib.suppress(Exception):
+            import matplotlib
+
+            if matplotlib.get_backend() != mpl_backend:
+                matplotlib.use(mpl_backend, force=True)
+
     if not mne_version_good:
         out(
             "\nTo update to the latest supported release version to get bugfixes and "