Quake III Arena is a 1999 multiplayer-focused first-person shooter developed by id Software. It is the third game in the Quake series and also the first spin-off to Quake; it differs from previous games by excluding a story-based single-player mode and highly focusing on multiplayer gameplay. The single-player mode is played against computer-controlled bots. It features music composed by Sonic Mayhem and Front Line Assembly founder Bill Leeb.

Notable features of Quake III Arena include the minimalist design, lacking rarely used items and features, the extensive customizability of player settings such as field of view, texture detail and enemy model, and advanced movement features such as strafe-jumping and rocket-jumping.