Major Hayes is a fictional character from the TV program Star Trek: Enterprise, played by Steven Culp, a popular actor also seen in the 5th and 6th season of The West Wing, playing the Speaker of the House. He first appeared in the third season premiere "The Xindi".

Major Hayes is the leader of the elite MACO team that was assigned to Enterprise when it was sent to the Delphic Expanse. He has had rivalries with Lt. Reed, who thought that he was trying to take over security of Enterprise. He and Reed resolved their rivalry in "Harbinger". (Actually, since Reed was chief of security, he had authority over all MACOS on the ship - including Hayes, who grudgingly called Reed "sir" even though Hayes technically outranked Reed.)

Major Hayes was killed in the third season finale "Zero Hour", when a Xindi-Reptilian fired through him as he was beamed off of the Xindi ship, after rescuing Hoshi from the Xindi. He died aboard Enterprise, under Dr. Phlox's care. The actor, coincidentally, portrayed a character on JAG who also died in the same first-run broadcast week.

Hayes' first name has never been revealed, although we do know his first initial - the name patch on his uniform read "J. Hayes".