diff --git a/draftlogs/6094_fix.md b/draftlogs/6094_fix.md
new file mode 100644
index 00000000000..92fcf361fc6
--- /dev/null
+++ b/draftlogs/6094_fix.md
@@ -0,0 +1 @@
+ - Fix vertical spacing of legend items in horizontal mode [[#6094](https://github.com/plotly/plotly.js/pull/6094)]
diff --git a/src/components/legend/draw.js b/src/components/legend/draw.js
index 0f5e3538fe4..7d0ff625fb5 100644
--- a/src/components/legend/draw.js
+++ b/src/components/legend/draw.js
@@ -714,7 +714,6 @@ function computeLegendDimensions(gd, groups, traces, legendObj) {
                     offsetY += h;
                     maxWidthInGroup = Math.max(maxWidthInGroup, textGap + w);
                 });
-                maxGroupHeightInRow = Math.max(maxGroupHeightInRow, offsetY);
 
                 var next = maxWidthInGroup + itemGap;
 
@@ -730,6 +729,8 @@ function computeLegendDimensions(gd, groups, traces, legendObj) {
                     groupOffsetX = 0;
                     groupOffsetY += maxGroupHeightInRow + traceGroupGap;
                     maxGroupHeightInRow = offsetY;
+                } else {
+                    maxGroupHeightInRow = Math.max(maxGroupHeightInRow, offsetY);
                 }
 
                 Drawing.setTranslate(this, groupOffsetX, groupOffsetY);
diff --git a/test/image/baselines/z-legend-row-group-height.png b/test/image/baselines/z-legend-row-group-height.png
new file mode 100644
index 00000000000..56db7a5adee
Binary files /dev/null and b/test/image/baselines/z-legend-row-group-height.png differ
diff --git a/test/image/mocks/z-legend-row-group-height.json b/test/image/mocks/z-legend-row-group-height.json
new file mode 100644
index 00000000000..6d4657e09e8
--- /dev/null
+++ b/test/image/mocks/z-legend-row-group-height.json
@@ -0,0 +1,32 @@
+{
+  "data": [
+    {
+      "legendgroup": "A",
+      "name": "Long label in group A",
+      "y": [1, 2, 3, 4]
+    },
+    {
+      "legendgroup": "B",
+      "name": "b1",
+      "y": [2, 3, 4, 1]
+    },
+    {
+      "legendgroup": "B",
+      "name": "Very long label in another group",
+      "y": [3, 4, 1, 2]
+    },
+    {
+      "legendgroup": "B",
+      "name": "b3",
+      "y": [4, 1, 2, 3]
+    }
+  ],
+  "layout": {
+    "paper_bgcolor": "lightblue",
+    "height": 350,
+    "width": 350,
+    "legend": {
+      "orientation": "h"
+    }
+  }
+}