In Doom RPG and in the extended Doom 3 universe, Ian Kelliher is the CEO and president of the Union Aerospace Corporation. A cold, precise person, Kelliher is very controlling of UAC activities on Mars, Earth, and the Moon. He acts authoritatively with most of the people of the UAC, especially with General Hayden, and is considered the most powerful person on Earth, even more so than the president of the United States, having "more money than God." Kelliher has a strange and cold relationship with his father, Thomas Kelliher, the founder of the UAC.
He is one of the few main characters in the Doom universe who is only mentioned but never appears in the games. He is named in one of the e-mails in Doom II RPG, and had a biography with a picture at the augmented reality "official site" of the UAC set up by id Software for the marketing of Doom RPG. He is also one of the main characters in the Doom 3 novels.