diff --git a/doc/conf.py b/doc/conf.py
index f3a50fd3518..0c8f65b7df7 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -128,6 +128,7 @@
     "newcontrib_substitutions",
     "unit_role",
     "related_software",
+    "directive_formatting",
 ]
 
 # Add any paths that contain templates here, relative to this directory.
diff --git a/doc/sphinxext/directive_formatting.py b/doc/sphinxext/directive_formatting.py
new file mode 100644
index 00000000000..a3090ab4c90
--- /dev/null
+++ b/doc/sphinxext/directive_formatting.py
@@ -0,0 +1,88 @@
+# Authors: The MNE-Python contributors.
+# License: BSD-3-Clause
+# Copyright the MNE-Python contributors.
+
+import re
+
+from mne_doc_utils import sphinx_logger
+
+
+def setup(app):
+    app.connect("source-read", check_directive_formatting)
+    app.connect("autodoc-process-docstring", check_directive_formatting)
+
+
+def setup_module():
+    # HACK: Stop nosetests running setup() above
+    pass
+
+
+def check_directive_formatting(*args):
+    """Check that directives are not missing a space.
+
+    For args, see Sphinx events 'source-read' and 'autodoc-process-docstring'.
+    """
+    # Extract relevant info from args
+    if len(args) == 3:  # from source-read
+        source_type = "File"
+        name = args[1]
+        source = args[2][0]
+        source_concat = source  # content already a single string
+    elif len(args) == 6:  # from autodoc-process-docstring
+        source_type = "Docstring"
+        name = args[2]
+        source = args[5]
+        source_concat = "\n".join(source)  # combine lines into single string
+    else:
+        raise RuntimeError("Unexpected number of arguments from Sphinx event")
+
+    # Check if any directives are present
+    if re.search(r"\.\.\s*[a-zA-Z]+::", source_concat) is None:
+        return
+
+    # Separate content into lines (docstrings already are)
+    if source_type == "File":
+        source = source.split("\n")
+
+    # Check for bad formatting
+    for idx, line in enumerate(source):
+        # Check for missing space after '..'
+        missing = re.search(r"\.\.[a-zA-Z]+::", line)
+        if missing is not None:
+            sphinx_logger.warning(
+                f"{source_type} '{name}' is missing a space after '..' in the "
+                f"directive '{missing.group()}'"
+            )
+        # Extra spaces after '..' don't affect formatting
+
+        # Check for missing preceding blank line
+        # (exceptions are for directives at the start of files, after a header, or after
+        # another directive/another directive's content)
+        if idx == 0:
+            continue
+        dir_pattern = r"\.\. [a-zA-Z]+::"
+        head_pattern = r"^[-|=|\^]+$"
+        directive = re.search(dir_pattern, line)
+        if directive is not None:
+            line_prev = source[idx - 1].strip()
+            if (  # If previous line is...
+                line_prev != ""  # not empty
+                and not re.search(head_pattern, line_prev)  # not a header
+                and not re.search(dir_pattern, line_prev)  # not a directive
+            ):
+                # Check if previous line is part of another directive
+                bad = True
+                for line_prev in reversed(source[: idx - 1]):
+                    line_prev = line_prev.strip()
+                    if line_prev == "" or re.search(head_pattern, line_prev):
+                        # is a blank line or header, so not part of another directive
+                        break  # must be bad formatting
+                    if re.search(dir_pattern, line_prev):
+                        bad = False  # is part of another directive, is good formatting
+                        break
+                    # or keep going until we reach the first line (so must be bad)
+                if bad:
+                    sphinx_logger.warning(
+                        f"{source_type} '{name}' is missing a blank line before the "
+                        f"directive '{directive.group()}'"
+                    )
diff --git a/examples/preprocessing/css.py b/examples/preprocessing/css.py
index ba4e2385d0c..c6684b74273 100644
--- a/examples/preprocessing/css.py
+++ b/examples/preprocessing/css.py
@@ -99,6 +99,7 @@ def subcortical_waveform(times):
 ax.set(ylabel="EEG Power spectral density", xlabel="Frequency (Hz)")
 ax.legend()
 
+###############################################################################
 # References
 # ^^^^^^^^^^
 #
diff --git a/examples/time_frequency/compute_source_psd_epochs.py b/examples/time_frequency/compute_source_psd_epochs.py
index 0fa7558e9f4..21901e82eaa 100644
--- a/examples/time_frequency/compute_source_psd_epochs.py
+++ b/examples/time_frequency/compute_source_psd_epochs.py
@@ -72,7 +72,7 @@
 # Compute source space PSD in label
 # ---------------------------------
 #
-# ..note:: By using "return_generator=True" stcs will be a generator object
+# .. note:: By using "return_generator=True" stcs will be a generator object
 #          instead of a list. This allows us so to iterate without having to
 #          keep everything in memory.
 
diff --git a/mne/epochs.py b/mne/epochs.py
index c042715e6ae..d6159f49583 100644
--- a/mne/epochs.py
+++ b/mne/epochs.py
@@ -2211,6 +2211,7 @@ def save(
         -------
         fnames : List of path-like
             List of path-like objects containing the path to each file split.
+
             .. versionadded:: 1.9
 
         Notes
diff --git a/mne/io/base.py b/mne/io/base.py
index 29852d38863..eb2b5bc49f3 100644
--- a/mne/io/base.py
+++ b/mne/io/base.py
@@ -1755,6 +1755,7 @@ def save(
         -------
         fnames : List of path-like
             List of path-like objects containing the path to each file split.
+
             .. versionadded:: 1.9
 
         Notes
diff --git a/mne/io/egi/egi.py b/mne/io/egi/egi.py
index 433758e19bf..73e93d39460 100644
--- a/mne/io/egi/egi.py
+++ b/mne/io/egi/egi.py
@@ -131,6 +131,7 @@ def read_raw_egi(
         Channel naming convention for the data channels. Defaults to ``'E%%d'``
         (resulting in channel names ``'E1'``, ``'E2'``, ``'E3'``...). The
         effective default prior to 0.14.0 was ``'EEG %%03d'``.
+
         .. versionadded:: 0.14.0
 
     events_as_annotations : bool
diff --git a/mne/io/nicolet/nicolet.py b/mne/io/nicolet/nicolet.py
index f55cd77061d..05b8035bddd 100644
--- a/mne/io/nicolet/nicolet.py
+++ b/mne/io/nicolet/nicolet.py
@@ -21,7 +21,7 @@ def read_raw_nicolet(
 ) -> "RawNicolet":
     """Read Nicolet data as raw object.
 
-    ..note:: This reader takes data files with the extension ``.data`` as an
+    .. note:: This reader takes data files with the extension ``.data`` as an
              input. The header file with the same file name stem and an
              extension ``.head`` is expected to be found in the same
              directory.
diff --git a/mne/label.py b/mne/label.py
index 02bf9dc09c0..2d55de755c0 100644
--- a/mne/label.py
+++ b/mne/label.py
@@ -949,7 +949,7 @@ def compute_area(
 
         Notes
         -----
-        ..versionadded:: 0.24
+        .. versionadded:: 0.24
         """
         _, _, surf = self._load_surface(
             subject, subjects_dir, surface, return_dict=True