Worn by: George Clooney as Matt Kowalski
Reference: Omega Speedmaster
Brand: Omega
George Clooney's character, Matt Kowalski, wears an Omega Speedmaster Professional in Gravity. Of course, as an Omega ambassador, there was only one watch of choice for Clooney. The Speedy is sewn into his spacesuit with only the watch head visible. Curiously, the watch in the film is also missing the tachymeter bezel. Whether this was a stylistic choice for the character or a decision made during production, it's noticeably absent and actually looks pretty cool.
Source: https://www.fratellowatches.com/speedmaster-in-movies/