Okay, I don't think everyone needs to say the same answer over and over again o_o Bluedevil, that's his Spartan No., not his name XD They never said his last name, but he would've probably been called John Bungie if they had their way, you all know it.
Master Chief's real name is Bill Nye the science guy.IT IS TRUE I ACCUALY MET HIM IN THE 360. ____________________________________________________________
Not Masterchef (although I'm so glad he's gone), Master Chief! Y'know, the main character from the Halo game series. Also, zander is correct. They indiscretely mention it throughout all of the games. His name is John
See, he can quit from WoW for a few seconds to look up info on Halo.
John-117. He was a military "test-subject" as a child. His last name is irrelevant, and he is called 117 just as often as John. I got this information from the first of three Halo novels.