The One Direction star uploaded the arty black and white shot to Instagram overnight with the simple caption "lucky."
In the photo, Louis is seen planting a kiss on US actress Danielle's cheek, while she beams at the camera, one hand resting on his chin.
In just nine hours the image garnered more than 700,000 likes and nearly 90,000 comments from Louis' followers.
The photo was taken during weekend two at the Coachella Music Festival in California.
Louis, 24, has been dating Danielle, 21, for the past few months but although they've been seen out and about together in paparazzi photos, they hadn't shared any pictures to social media until now.
Danielle is best known for her roles in TV show The Originals and Disney Channel Original Movie StarStruck. She began dating Louis shortly before the January birth of his first child, Freddie Reign, with former flame Briana Jungwirth.