diff --git a/doc/users/whats_new/anchoredsizebar_fill_bar_argument.rst b/doc/users/whats_new/anchoredsizebar_fill_bar_argument.rst
new file mode 100644
index 000000000000..7426f2b25978
--- /dev/null
+++ b/doc/users/whats_new/anchoredsizebar_fill_bar_argument.rst
@@ -0,0 +1,13 @@
+Add fill_bar argument to ``AnchoredSizeBar``
+--------------------------------------------
+
+The mpl_toolkits class
+:class:`~mpl_toolkits.axes_grid1.anchored_artists.AnchoredSizeBar` now has an
+additional ``fill_bar`` argument, which makes the size bar a solid rectangle
+instead of just drawing the border of the rectangle. The default is ``None``,
+and whether or not the bar will be filled by default depends on the value of
+``size_vertical``. If ``size_vertical`` is nonzero, ``fill_bar`` will be set to
+``True``. If ``size_vertical`` is zero then ``fill_bar`` will be set to
+``False``. If you wish to override this default behavior, set ``fill_bar`` to
+``True`` or ``False`` to unconditionally always or never use a filled patch
+rectangle for the size bar.
diff --git a/lib/mpl_toolkits/axes_grid1/anchored_artists.py b/lib/mpl_toolkits/axes_grid1/anchored_artists.py
index ac5eaf29039e..3cda87108377 100644
--- a/lib/mpl_toolkits/axes_grid1/anchored_artists.py
+++ b/lib/mpl_toolkits/axes_grid1/anchored_artists.py
@@ -232,7 +232,7 @@ class AnchoredSizeBar(AnchoredOffsetbox):
     def __init__(self, transform, size, label, loc,
                  pad=0.1, borderpad=0.1, sep=2,
                  frameon=True, size_vertical=0, color='black',
-                 label_top=False, fontproperties=None,
+                 label_top=False, fontproperties=None, fill_bar=None,
                  **kwargs):
         """
         Draw a horizontal scale bar with a center-aligned label underneath.
@@ -295,6 +295,12 @@ def __init__(self, transform, size, label, loc,
         fontproperties : `matplotlib.font_manager.FontProperties`, optional
             Font properties for the label text.
 
+        fill_bar : bool, optional
+            If True and if size_vertical is nonzero, the size bar will
+            be filled in with the color specified by the size bar.
+            Defaults to True if `size_vertical` is greater than
+            zero and False otherwise.
+
         **kwargs :
             Keyworded arguments to pass to
             :class:`matplotlib.offsetbox.AnchoredOffsetbox`.
@@ -334,9 +340,12 @@ def __init__(self, transform, size, label, loc,
 size_vertical=0.5, color='white', \
 fontproperties=fontprops)
         """
+        if fill_bar is None:
+            fill_bar = size_vertical > 0
+
         self.size_bar = AuxTransformBox(transform)
         self.size_bar.add_artist(Rectangle((0, 0), size, size_vertical,
-                                           fill=False, facecolor=color,
+                                           fill=fill_bar, facecolor=color,
                                            edgecolor=color))
 
         if fontproperties is None and 'prop' in kwargs: