A touching father-and-son photo is making the rounds online after taking the top spot in the "Best Bald Dad" contest put on by a U.S. childhood cancer foundation.

Josh Marshall of Kansas got a tattoo on the side of his head to match his son's scar from brain cancer surgery.

Marshall said he got the tattoo to help boost eight-year-old Gabriel's self-confidence.

The photo was entered in the St. Baldrick's Foundation's Best Bald Dad contest that sought submissions from men who have shaved their head in honour of a child who is battling cancer.

Marshall won the contest with more than 5,000 likes.

He told local media that Gabriel was very self-conscious after undergoing surgery to remove a brain tumour that left him with a large, horseshoe shaped-scar over his right ear.

Marshall said he got the tattoo so people who stared at Gabriel could stare at him, too.

Gabriel reportedly finished his cancer treatments about nine months ago. Marshall said a small tumour remains in Gabriel’s brain, but it hasn’t grown.   

The photo posted online has prompted hundreds of comments, with many individuals remarking on how the moving gesture perfectly captures the strong father-son bond.