Ace Combat 3: Electrosphere is a combat flight simulation video game developed and published by Namco for the PlayStation. The third game in the Ace Combat franchise, it was released in Japan on May 27, 1999 and internationally the following year. Players fly fighter aircraft and must complete a variety of mission objectives, such as destroying squadrons of enemy planes or protecting a base from an invading unit.

Namco directors Takuya Iwasaki and Atsushi Shiozawa designed Electrosphere to be visually distinct from other combat flight simulators, using Ace Combat 2 as a base for the game's ideas and mechanics. The storyline was designed to be a core aspect of the game, and to serve a proper purpose by directly affecting the gameplay. Electrosphere carries a futuristic science fiction-inspired landscape and world compared to the modern-day theme of its predecessors. The game is infamous for its drastic differences in content in the Japanese and international releases; Namco intended to retain the Japanese version's two-disc campaign and larger story, but due to financial constraints the game was cut down for North America and Europe.

Though it had a small marketing campaign and little promotion, Electrosphere shipped over one million copies. The Japanese release received positive reviews and was seen as ambitious in its design. International releases were more mixed, with critics expressing confusion towards the lack of content and bland gameplay. In retrospect, Electrosphere has been well-received, with critics identifying and appreciating its ambition, story, and changes to the gameplay of the series.