The Lexus GS (S190) is the third generation of the Lexus GS line of executive cars. Sold by Lexus from 2005 to 2011, the line includes multiple V6, V8, and hybrid models. A concept model for the GS line, the LF-S, debuted in late 2003 at the Tokyo Motor Show. The third generation GS first appeared as a pre-production vehicle at the 2004 North American International Auto Show in Detroit with the production version being shown a year later at the 2005 show. The initial lineup featured V6 and V8 engines with rear-wheel drive, and for the first time on a Lexus sedan, the option of all-wheel drive with the V6-powered GS 300 and GS 350 models. The GS 450h performance hybrid joined the lineup in 2006.

The Lexus GS is an executive car manufactured and marketed by Lexus across four generations — launched in 1991 as the Toyota Aristo in Japan and as the Lexus GS for markets outside the Japanese market beginning in February 1993. It continued with the Toyota Aristo name for the Japanese market until January 2005.