The Lexus GS is a series of mid-size luxury sports sedans / executive cars sold by Lexus since 1993. Designed to fill the gap between the ES and LS, and to provide Lexus with a sports sedan to compete in the mid-size class, three generations of the GS have been produced to date. The first GS, based on the platform and running gear of the Toyota Crown, was introduced in 1993 in the United States, Europe and selected markets in Asia. The second generation model premiered in 1998, using a new platform and adding a V8 version for the first time outside Japan. The current third generation GS, which premiered globally for the 2006 model year, comes in both V6, V8, and hybrid versions, the latter known as the GS 450h performance hybrid.

In Japan, the equivalent Toyota Aristo, which debuted in 1991, was sold until the introduction of the Lexus marque and the third generation GS in 2005. Following the debut of the third generation GS in Japan, the Aristo was discontinued. Though largely identical in exterior and interior design, first two generations of the GS and the Aristo differed in their engine and transmission combinations as well as equipment packages. Competitors to the Lexus GS include the BMW 5-Series and the Mercedes-Benz E-Class.

With a body styled by the famous Italdesign Giugiaro firm, the Aristo was launched in October 1991, offering two inline-6 powered versions for the Japanese market: the 3.0Q and 3.0V. The 3.0Q Aristo featured a 2JZ-GE engine which produced 226hp (169kW). The 3.0V Aristo was equipped with a 24-valve twin-turbo 2JZ-GTE engine which produced 276hp (205kW). This twin-turbo engine was the same as could be found in the Toyota Supra Mk IV (JZA80). In 1992, a third model, the V8-powered 4.0Zi-Four (codename UZS143), joined the Aristo lineup. This model came with standard four-wheel drive and a 250 hp (186 kW) 1UZ-FE engine. This V8 had also been used in the first generation Lexus LS and the Toyota Crown Majesta. The Aristo/GS models were equipped with an independent, double-wishbone suspension setup. The only engine available for the export markets was the 2JZ-GE inline-6.