diff --git a/lib/matplotlib/axes/_base.py b/lib/matplotlib/axes/_base.py
index f9c3c25bbff5..394dfc2ccafd 100644
--- a/lib/matplotlib/axes/_base.py
+++ b/lib/matplotlib/axes/_base.py
@@ -3229,7 +3229,7 @@ def grid(self, visible=None, which='major', axis='both', **kwargs):
         if axis in ['y', 'both']:
             self.yaxis.grid(visible, which=which, **kwargs)
 
-    def ticklabel_format(self, *, axis='both', style='', scilimits=None,
+    def ticklabel_format(self, *, axis='both', style=None, scilimits=None,
                          useOffset=None, useLocale=None, useMathText=None):
         r"""
         Configure the `.ScalarFormatter` used by default for linear Axes.
@@ -3245,6 +3245,7 @@ def ticklabel_format(self, *, axis='both', style='', scilimits=None,
         style : {'sci', 'scientific', 'plain'}
             Whether to use scientific notation.
             The formatter default is to use scientific notation.
+            'sci' is equivalent to 'scientific'.
 
         scilimits : pair of ints (m, n)
             Scientific notation is used only for numbers outside the range
@@ -3274,7 +3275,8 @@ def ticklabel_format(self, *, axis='both', style='', scilimits=None,
         AttributeError
             If the current formatter is not a `.ScalarFormatter`.
         """
-        style = style.lower()
+        if isinstance(style, str):
+            style = style.lower()
         axis = axis.lower()
         if scilimits is not None:
             try:
@@ -3283,7 +3285,8 @@ def ticklabel_format(self, *, axis='both', style='', scilimits=None,
             except (ValueError, TypeError) as err:
                 raise ValueError("scilimits must be a sequence of 2 integers"
                                  ) from err
-        STYLES = {'sci': True, 'scientific': True, 'plain': False, '': None}
+        STYLES = {'sci': True, 'scientific': True, 'plain': False, '': None, None: None}
+        # The '' option is included for backwards-compatibility.
         is_sci_style = _api.check_getitem(STYLES, style=style)
         axis_map = {**{k: [v] for k, v in self._axis_map.items()},
                     'both': list(self._axis_map.values())}
diff --git a/lib/matplotlib/axes/_base.pyi b/lib/matplotlib/axes/_base.pyi
index e3644585296d..1f929b6c90c5 100644
--- a/lib/matplotlib/axes/_base.pyi
+++ b/lib/matplotlib/axes/_base.pyi
@@ -283,7 +283,7 @@ class _AxesBase(martist.Artist):
         self,
         *,
         axis: Literal["both", "x", "y"] = ...,
-        style: Literal["", "sci", "scientific", "plain"] = ...,
+        style: Literal["", "sci", "scientific", "plain"] | None = ...,
         scilimits: tuple[int, int] | None = ...,
         useOffset: bool | float | None = ...,
         useLocale: bool | None = ...,
diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
index 00e5dea071a4..74a73725d5d9 100644
--- a/lib/matplotlib/pyplot.py
+++ b/lib/matplotlib/pyplot.py
@@ -3953,7 +3953,7 @@ def tick_params(axis: Literal["both", "x", "y"] = "both", **kwargs) -> None:
 def ticklabel_format(
     *,
     axis: Literal["both", "x", "y"] = "both",
-    style: Literal["", "sci", "scientific", "plain"] = "",
+    style: Literal["", "sci", "scientific", "plain"] | None = None,
     scilimits: tuple[int, int] | None = None,
     useOffset: bool | float | None = None,
     useLocale: bool | None = None,