Quake III Arena is a 1999 multiplayer-focused first-person shooter developed by id Software. The third installment of the Quake series, Arena differs from previous games by excluding a story-based single-player mode and focusing primarily 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 a minimalist design, very extensively customizable settings such as field of view, texture detail and enemy model; and advanced movement features such as strafe-jumping and rocket-jumping.

The game was praised by reviewers who, for the most part, described the gameplay as fun and engaging. Many liked the crisp graphics and focus on multiplayer. Quake III Arena, often being considered one of the greatest video games ever made, has also been used extensively in professional electronic sports tournaments such as QuakeCon, Cyberathlete Professional League, DreamHack, and the Electronic Sports World Cup.