diff --git a/modules/geometry/src/geometry.cpp b/modules/geometry/src/geometry.cpp
index 5cba72c35d..c9073c2aa2 100644
--- a/modules/geometry/src/geometry.cpp
+++ b/modules/geometry/src/geometry.cpp
@@ -504,7 +504,7 @@ double arcLength( InputArray _curve, bool is_closed )
 
 static Rect maskBoundingRect( const Mat& img )
 {
-    CV_Assert( img.depth() <= CV_8S && img.channels() == 1 );
+    CV_Assert( (img.depth() <= CV_8S || img.depth() == CV_Bool) && img.channels() == 1 );
 
     Size size = img.size();
     int xmin = size.width, ymin = -1, xmax = -1, ymax = -1, i, j, k;
@@ -709,7 +709,10 @@ cv::Rect boundingRect(InputArray array)
     CV_INSTRUMENT_REGION();
 
     Mat m = array.getMat();
-    return m.depth() <= CV_8U ? maskBoundingRect(m) : pointSetBoundingRect(m);
+    // CV_Bool is a 1-byte mask type (added in 5.0); route it through the
+    // byte-wise mask path, same as CV_8U/CV_8S. See #29578.
+    int depth = m.depth();
+    return (depth <= CV_8U || depth == CV_Bool) ? maskBoundingRect(m) : pointSetBoundingRect(m);
 }
 
 cv::Matx23d getRotationMatrix2D_(Point2f center, double angle, double scale)
diff --git a/modules/geometry/test/test_boundingrect.cpp b/modules/geometry/test/test_boundingrect.cpp
index cf70b66e04..0bc8e55b7d 100644
--- a/modules/geometry/test/test_boundingrect.cpp
+++ b/modules/geometry/test/test_boundingrect.cpp
@@ -96,4 +96,31 @@ TEST(Imgproc_BoundingRect, bug_24217)
     }
 }
 
+// See https://github.com/opencv/opencv/issues/29578
+// cv::Mat_<bool>::depth() returns CV_Bool in 5.0, which regressed boundingRect
+// (it used to be treated as CV_8U in 4.x). A boolean mask must be handled as a
+// byte-wise mask, matching the CV_8UC1 result.
+TEST(Imgproc_BoundingRect, bool_mask_29578)
+{
+    for (int image_width = 3; image_width < 20; image_width++)
+    {
+        for (int image_height = 1; image_height < 15; image_height++)
+        {
+            cv::Rect rect(0, image_height - 1, 3, 1);
+
+            cv::Mat_<bool> mask(cv::Size(image_width, image_height), false);
+            mask(rect).setTo(true);
+
+            cv::Mat_<uchar> ref(cv::Size(image_width, image_height), (uchar)0);
+            ref(rect).setTo(255);
+
+            EXPECT_EQ(mask.depth(), CV_Bool);
+            cv::Rect result;
+            ASSERT_NO_THROW(result = boundingRect(mask));
+            EXPECT_EQ(result, rect);
+            EXPECT_EQ(result, boundingRect(ref));
+        }
+    }
+}
+
 }} // namespace