diff --git a/src/ol/format/KML.js b/src/ol/format/KML.js
index 8775ecf583..84c9165075 100644
--- a/src/ol/format/KML.js
+++ b/src/ol/format/KML.js
@@ -126,7 +126,7 @@ const PLACEMARK_PARSERS = makeStructureNS(
     'name': makeObjectPropertySetter(readString),
     'open': makeObjectPropertySetter(readBoolean),
     'phoneNumber': makeObjectPropertySetter(readString),
-    'styleUrl': makeObjectPropertySetter(readURI),
+    'styleUrl': makeObjectPropertySetter(readStyleURL),
     'visibility': makeObjectPropertySetter(readBoolean),
   },
   makeStructureNS(GX_NAMESPACE_URIS, {
@@ -1074,12 +1074,6 @@ function findStyle(styleValue, defaultStyle, sharedStyles) {
   if (Array.isArray(styleValue)) {
     return styleValue;
   } else if (typeof styleValue === 'string') {
-    // KML files in the wild occasionally forget the leading `#` on styleUrls
-    // defined in the same document.  Add a leading `#` if it enables to find
-    // a style.
-    if (!(styleValue in sharedStyles) && '#' + styleValue in sharedStyles) {
-      styleValue = '#' + styleValue;
-    }
     return findStyle(sharedStyles[styleValue], defaultStyle, sharedStyles);
   } else {
     return defaultStyle;
@@ -1151,6 +1145,28 @@ function readURI(node) {
   }
 }
 
+/**
+ * @param {Node} node Node.
+ * @return {string} URI.
+ */
+function readStyleURL(node) {
+  // KML files in the wild occasionally forget the leading
+  // `#` on styleUrlsdefined in the same document.
+  const s = getAllTextContent(node, false)
+    .trim()
+    .replace(/^(?!.*#)/, '#');
+  let baseURI = node.baseURI;
+  if (!baseURI || baseURI == 'about:blank') {
+    baseURI = window.location.href;
+  }
+  if (baseURI) {
+    const url = new URL(s, baseURI);
+    return url.href;
+  } else {
+    return s;
+  }
+}
+
 /**
  * @param {Element} node Node.
  * @return {Vec2} Vec2.
@@ -2021,7 +2037,7 @@ function regionParser(node, objectStack) {
 const PAIR_PARSERS = makeStructureNS(NAMESPACE_URIS, {
   'Style': makeObjectPropertySetter(readStyle),
   'key': makeObjectPropertySetter(readString),
-  'styleUrl': makeObjectPropertySetter(readURI),
+  'styleUrl': makeObjectPropertySetter(readStyleURL),
 });
 
 /**
diff --git a/test/spec/ol/format/kml.test.js b/test/spec/ol/format/kml.test.js
index 0fe434e3f6..b92db81e39 100644
--- a/test/spec/ol/format/kml.test.js
+++ b/test/spec/ol/format/kml.test.js
@@ -3477,6 +3477,41 @@ describe('ol.format.KML', function () {
           expect(s.getFill().getColor()).to.eql([120, 86, 52, 18 / 255]);
         });
 
+        it('can use Styles in StyleMaps if # is missing', function () {
+          const text =
+            '<kml xmlns="http://earth.google.com/kml/2.2">' +
+            '  <Document>' +
+            '    <StyleMap id="fooMap">' +
+            '      <Pair>' +
+            '        <key>normal</key>' +
+            '        <styleUrl>foo</styleUrl>' +
+            '      </Pair>' +
+            '    </StyleMap>' +
+            '    <Style id="foo">' +
+            '      <PolyStyle>' +
+            '        <color>12345678</color>' +
+            '      </PolyStyle>' +
+            '    </Style>' +
+            '    <Placemark>' +
+            '      <styleUrl>fooMap</styleUrl>' +
+            '    </Placemark>' +
+            '  </Document>' +
+            '</kml>';
+          const fs = format.readFeatures(text);
+          expect(fs).to.have.length(1);
+          const f = fs[0];
+          expect(f).to.be.an(Feature);
+          const styleFunction = f.getStyleFunction();
+          expect(styleFunction).not.to.be(undefined);
+          const styleArray = styleFunction(f, 0);
+          expect(styleArray).to.be.an(Array);
+          expect(styleArray).to.have.length(1);
+          const s = styleArray[0];
+          expect(s).to.be.an(Style);
+          expect(s.getFill()).not.to.be(null);
+          expect(s.getFill().getColor()).to.eql([120, 86, 52, 18 / 255]);
+        });
+
         it('can use IconStyles in StyleMaps before they are defined (and set the crossOrigin option)', function () {
           format = new KML({crossOrigin: null});
           const text =