Played by Steven Culp)
Commander of the Military Assault Command Operation (MACO) detachment assigned to the Enterprise NX-01 mission to the Delphic Expanse. Hayes clashed with Lt. Reed when the Major suggested that Reed's men were too valuable to take on a risky rescue mission. The rivalry between the two finally broke out into fisticuffs and had to be squashed by Capt. Archer. Hayes had the bridge conn briefly when Archer was intoxicated under a Xindi-Insectoid pot, but he was later shot and died while,rescuing Ens. Sato as the Xindi conflict drew to a climax.