Alfonso John Romero is an American director, designer, programmer and developer in the video game industry. He is a co-founder of id Software and designed their early games, including Wolfenstein 3D (1992), Doom (1993), Doom II (1994), Hexen (1995) and Quake (1996). His designs and development tools, along with programming techniques developed by id Software's lead programmer, John Carmack, popularized the first-person shooter (FPS) genre. Romero is also credited with coining the multiplayer term "deathmatch".

id Software LLC is an American video game developer based in Richardson, Texas. It was founded on February 1, 1991, by four members of the computer company Softdisk: programmers John Carmack and John Romero, game designer Tom Hall, and artist Adrian Carmack.