The 37-year-old actor marked the occasion Wednesday by sharing a childhood photo of himself and Liam Hemsworth.
Chris Hemsworth teased his brother by posting the throwback photo of them as kids on Instagram. The picture shows the pair smiling for the camera while wearing matching school uniforms.
"Happy birthday @liamhemsworth this photo was taken 3 years ago today, damn time flys but you haven't changed a bit," Chris Hemsworth captioned the post.
Liam Hemsworth, also an actor, posted a more recent photo with Chris Hemsworth in December while celebrating Christmas with family. The picture shows Liam Hemsworth smiling for the camera as Chris Hemsworth faces the opposite direction.
"Merry Christmas everyone! Lots of love. Enjoy your time with family and friends. Great conversation with @chrishemsworth," Liam Hemsworth jokingly wrote.
Chris Hemsworth and Liam Hemsworth also have another brother, actor Luke Hemsworth, 40. Luke Hemsworth discussed his brothers in an interview with Jimmy Kimmel Live! in February, saying he would beat them up as kids.
"Every chance I could, and I still do. They're really tall, but they're actually quite soft. And they cry a lot. I take great joy in making them cry," he jokingly said.
Liam Hemsworth is known for playing Gale Hawthorne in the Hunger Games film series, while Chris Hemsworth portrays Thor in the Marvel Cinematic Universe. Luke Hemsworth plays Ashley Stubbs on the HBO series Westworld.
In a 2019 interview with GQ Australia, Liam Hemsworth recalled losing the role of Thor to Chris Hemsworth.
"I never really wanted to do it," he said. "I always felt I was too young for it -- I was screen testing when I was 18. The other guys in it were all late 20s or early 30s. I didn't feel Thor-ish."