| ||For other characters named Alex in the Fallout universe, see Alex.|
Alex Keller is part of the Keller family. He does not actually appear in the game, but is mentioned in the Keller family transcript.
Alex was a National Guardsman, who stole the bunker codes, so his family was able to survive nuclear holocaust. Unfortunately, he was caught; but before he was taken into custody, he sent each member of his family a single digit of the code. This way, they would all have to be there to get in.
Alex Keller does not actually appear in any game, but is mentioned in Fallout 3.