diff --git a/__test__/Gallery.test.js b/__test__/Gallery.test.js
index 6a58eea..432f2f5 100644
--- a/__test__/Gallery.test.js
+++ b/__test__/Gallery.test.js
@@ -37,4 +37,15 @@ describe('Gallery', () => {
     wrapper = mount(<Gallery photos={photos} onClick={handleClick} columns={columns} direction="column" />);
     expect(columns).toBeCalledWith(1140);
   });
+
+  it('calls the callback when all images finish loading', () => {
+    const callback = jest.fn();
+    wrapper = mount(<Gallery photos={photos} onClick={handleClick} direction="column" onLoadCallback={callback} />);
+    let images = wrapper.find('img');
+    images.forEach(node => {
+      node.simulate('load');
+    });
+
+    expect(callback).toHaveBeenCalled();
+  });
 });
diff --git a/__test__/__snapshots__/Gallery.test.js.snap b/__test__/__snapshots__/Gallery.test.js.snap
index 290171a..fbca1fd 100644
--- a/__test__/__snapshots__/Gallery.test.js.snap
+++ b/__test__/__snapshots__/Gallery.test.js.snap
@@ -328,6 +328,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="40673436833"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673436833_5fc1ab52fe_b.jpg"
         srcSet={
@@ -353,6 +354,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="47587238132"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238132_4683fdabb2_b.jpg"
         srcSet={
@@ -378,6 +380,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="32697497947"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497947_7d6dfaf5ec_b.jpg"
         srcSet={
@@ -403,6 +406,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="32697497647"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497647_31cd88c0b5_b.jpg"
         srcSet={
@@ -428,6 +432,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="47587238242"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238242_6776b8a582_b.jpg"
         srcSet={
@@ -453,6 +458,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="40673437163"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437163_703ffe416d_b.jpg"
         srcSet={
@@ -478,6 +484,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={332.64705882352945}
         key="47587238362"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238362_5d355937cb_b.jpg"
         srcSet={
@@ -503,6 +510,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={332.64705882352945}
         key="32697498187"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697498187_7a74849c76_b.jpg"
         srcSet={
@@ -528,6 +536,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={241.32762312633832}
         key="40673436913"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673436913_c48ac9e6d5_b.jpg"
         srcSet={
@@ -553,6 +562,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={241.32762312633832}
         key="40673437213"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437213_3480e88c8b_b.jpg"
         srcSet={
@@ -578,6 +588,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={241.32762312633832}
         key="47587238482"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238482_5ac51de790_b.jpg"
         srcSet={
@@ -603,6 +614,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={252.1252796420582}
         key="32697498227"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697498227_a3bc50aa6c_b.jpg"
         srcSet={
@@ -628,6 +640,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={252.1252796420582}
         key="40673437263"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437263_b03be98bae_b.jpg"
         srcSet={
@@ -653,6 +666,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={252.1252796420582}
         key="32697497717"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497717_1fb25b32be_b.jpg"
         srcSet={
@@ -678,6 +692,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="47587238552"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238552_cfce31cc10_b.jpg"
         srcSet={
@@ -703,6 +718,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="47640016631"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47640016631_cfffe28dd0_b.jpg"
         srcSet={
@@ -728,6 +744,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={250.44444444444446}
         key="47640017061"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47640017061_d6f554a175_b.jpg"
         srcSet={
@@ -753,6 +770,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={254.4018058690745}
         key="32697497787"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497787_ebd9165050_b.jpg"
         srcSet={
@@ -778,6 +796,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={254.4018058690745}
         key="40673437303"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437303_ec8b5a7246_b.jpg"
         srcSet={
@@ -803,6 +822,7 @@ exports[`Gallery it matches correct snapshot 1`] = `
         height={254.4018058690745}
         key="46724351385"
         onClick={[Function]}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/46724351385_a6ff50ddda_b.jpg"
         srcSet={
@@ -1154,6 +1174,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="40673436833"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673436833_5fc1ab52fe_b.jpg"
         srcSet={
@@ -1181,6 +1202,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="47587238132"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238132_4683fdabb2_b.jpg"
         srcSet={
@@ -1208,6 +1230,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="32697497947"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497947_7d6dfaf5ec_b.jpg"
         srcSet={
@@ -1235,6 +1258,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="32697497647"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497647_31cd88c0b5_b.jpg"
         srcSet={
@@ -1262,6 +1286,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="47587238242"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238242_6776b8a582_b.jpg"
         srcSet={
@@ -1289,6 +1314,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="40673437163"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437163_703ffe416d_b.jpg"
         srcSet={
@@ -1316,6 +1342,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="47587238362"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238362_5d355937cb_b.jpg"
         srcSet={
@@ -1343,6 +1370,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={197.7}
         key="32697498187"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697498187_7a74849c76_b.jpg"
         srcSet={
@@ -1370,6 +1398,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="40673436913"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673436913_c48ac9e6d5_b.jpg"
         srcSet={
@@ -1397,6 +1426,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={225}
         key="40673437213"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437213_3480e88c8b_b.jpg"
         srcSet={
@@ -1424,6 +1454,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="47587238482"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238482_5ac51de790_b.jpg"
         srcSet={
@@ -1451,6 +1482,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="32697498227"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697498227_a3bc50aa6c_b.jpg"
         srcSet={
@@ -1478,6 +1510,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={255.6}
         key="40673437263"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437263_b03be98bae_b.jpg"
         srcSet={
@@ -1505,6 +1538,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="32697497717"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497717_1fb25b32be_b.jpg"
         srcSet={
@@ -1532,6 +1566,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="47587238552"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47587238552_cfce31cc10_b.jpg"
         srcSet={
@@ -1559,6 +1594,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="47640016631"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47640016631_cfffe28dd0_b.jpg"
         srcSet={
@@ -1586,6 +1622,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="47640017061"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/47640017061_d6f554a175_b.jpg"
         srcSet={
@@ -1613,6 +1650,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={166.2}
         key="32697497787"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/32697497787_ebd9165050_b.jpg"
         srcSet={
@@ -1640,6 +1678,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={560.9}
         key="40673437303"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/40673437303_ec8b5a7246_b.jpg"
         srcSet={
@@ -1667,6 +1706,7 @@ exports[`Gallery renders correctly with direction set to column 1`] = `
         height={250.4}
         key="46724351385"
         onClick={null}
+        onLoad={[Function]}
         sizes="(min-width: 480px) 50vw, (min-width: 1024px) 33.3vw, 100vw"
         src="https://live.staticflickr.com/65535/46724351385_a6ff50ddda_b.jpg"
         srcSet={
diff --git a/examples/src/ExampleBasic.js b/examples/src/ExampleBasic.js
index 1b258a3..020208e 100644
--- a/examples/src/ExampleBasic.js
+++ b/examples/src/ExampleBasic.js
@@ -1,11 +1,11 @@
 import React from 'react';
 import Gallery from 'react-photo-gallery';
 
-const ExampleBasic = ({photos, title, direction}) => {
+const ExampleBasic = ({ photos, title, direction, onLoadCallback }) => {
     return (
       <div>
         <h2>{title}</h2>
-        <Gallery photos={photos} direction={direction}/>
+        <Gallery photos={photos} direction={direction} onLoadCallback={onLoadCallback}/>
       </div>
     );
 }
diff --git a/examples/src/app.js b/examples/src/app.js
index db4872d..0436a0f 100644
--- a/examples/src/app.js
+++ b/examples/src/app.js
@@ -60,9 +60,12 @@ class App extends React.Component {
   render() {
     if (this.state.photos) {
       const width = this.state.width;
+      const onLoad = () => {
+        console.log('Finished Loading Images');
+      }
       return (
         <div className="App">
-          <ExampleBasic title={'Basic Row Layout'} photos={this.state.photos.slice(0, 20)} />
+          <ExampleBasic title={'Basic Row Layout'} photos={this.state.photos.slice(0, 20)} onLoadCallback={onLoad} />
           <ExampleBasic title={'Basic Column Layout'} direction="column" photos={this.state.photos.slice(40, 60)} />
           <ExampleWithLightbox photos={this.state.photos.slice(60, 75)} />
           <ExampleCustomComponentSelection photos={this.state.photos.slice(75, 90)} />
diff --git a/src/Gallery.js b/src/Gallery.js
index b5475d9..2f2a7d8 100644
--- a/src/Gallery.js
+++ b/src/Gallery.js
@@ -15,9 +15,11 @@ const Gallery = React.memo(function Gallery({
   targetRowHeight,
   columns,
   renderImage,
+  onLoadCallback,
 }) {
   const [containerWidth, setContainerWidth] = useState(0);
   const galleryEl = useRef(null);
+  let loadedCount = 0;
 
   useLayoutEffect(() => {
     let animationFrameID = null;
@@ -48,6 +50,13 @@ const Gallery = React.memo(function Gallery({
     });
   };
 
+  const onImageLoaded = () => {
+    loadedCount++;
+    if (onLoadCallback && typeof onLoadCallback === 'function' && loadedCount === photos.length) {
+      onLoadCallback();
+    }
+  };
+
   // no containerWidth until after first render with refs, skip calculations and render nothing
   if (!containerWidth) return <div ref={galleryEl}>&nbsp;</div>;
   // subtract 1 pixel because the browser may round up a pixel
@@ -106,6 +115,7 @@ const Gallery = React.memo(function Gallery({
             direction,
             onClick: onClick ? handleClick : null,
             photo,
+            onImageLoaded,
           });
         })}
       </div>
@@ -122,6 +132,7 @@ Gallery.propTypes = {
   limitNodeSearch: PropTypes.oneOfType([PropTypes.func, PropTypes.number]),
   margin: PropTypes.number,
   renderImage: PropTypes.func,
+  onLoadCallback: PropTypes.func,
 };
 
 Gallery.defaultProps = {
diff --git a/src/Photo.js b/src/Photo.js
index 18e3d3f..03c52d6 100644
--- a/src/Photo.js
+++ b/src/Photo.js
@@ -3,7 +3,7 @@ import PropTypes from 'prop-types';
 
 const imgWithClick = { cursor: 'pointer' };
 
-const Photo = ({ index, onClick, photo, margin, direction, top, left, key }) => {
+const Photo = ({ index, onClick, photo, margin, direction, top, left, key, onImageLoaded }) => {
   const imgStyle = { margin: margin, display: 'block' };
   if (direction === 'column') {
     imgStyle.position = 'absolute';
@@ -21,6 +21,7 @@ const Photo = ({ index, onClick, photo, margin, direction, top, left, key }) =>
       style={onClick ? { ...imgStyle, ...imgWithClick } : imgStyle}
       {...photo}
       onClick={onClick ? handleClick : null}
+      onLoad={onImageLoaded ? onImageLoaded : null}
     />
   );
 };
@@ -52,6 +53,7 @@ Photo.propTypes = {
     }
   },
   direction: PropTypes.string,
+  onImageLoaded: PropTypes.func,
 };
 
 export default Photo;