The Infiniti Q45 is a full-size luxury sedan manufactured by Nissan for its Infiniti brand, spanning model years 1989-2006 and three design generations.

Infiniti is the luxury vehicle division of the Japanese automaker Nissan. Infiniti officially started selling vehicles on November 8, 1989, in North America. The marketing network for Infiniti-branded vehicles included dealers in over 50 countries in the 2010s. As of 2020, there were 25 markets served by new car dealers. The main markets are North America, China, Taiwan, and the Middle East.