After receiving lots of nice messages during the day over on X from drivers, fans and media alike, the Brit was greeted at the circuit by his team, who sang happy birthday and presented him with a card.
The card showed a picture of a young Horner sat naked on the front of the team's dominant RB19 car, striking a rather flattering pose. This edited photo from a magazine shoot in the early 2000s was later shown on Red Bull's official X page.
Horner joined the team in 2005 as team principal - after Jaguar F1 was bought by Austrian drinks company Red Bull - and he hasn't looked back since.
He has now won 13 world championships as Red Bull boss, including two this season with his star-driver Max Verstappen cruising to his third consecutive title.
He will be hoping that Red Bull can claim yet another victory in this record-breaking season at the Las Vegas GP.