ATI Technologies U.L.C. is a major designer and supplier of graphics processing units, motherboard chipsets, and video display cards. Founded in Canada in 1985, the company was bought by and merged into the micro-processor manufacturer AMD in 2006.

ATI was a fabless semiconductor company. The company conducts in-house research and development and outsourceed the manufacturing and assembly of its products. Its main competitor is NVIDIA in the graphics and handheld market. The flagship product, the Radeon series of graphics cards, directly competes with NVIDIA's GeForce. The two companies' dominance of the market forced other manufacturers into niche roles.