Steve "Luke" Lukather (born October 21, 1957, San Fernando Valley, California) is an American Grammy Award-winning guitarist, singer, songwriter, arranger, and record producer best known for his work with the rock band Toto. Lukather has played with countless artists, released several solo albums and, as a studio session guitarist, has been involved with arranging, composing, and recording on over 1,000 albums. He is also a member of jazz fusion bands El Grupo and Los Lobotomys, both collaborations of notable sessions musicians. While his work with Toto was predominantly based on pop rock music, Lukather's solo and side-project work spans many genres including rock, prog, jazz and funk.

Notable session keyboardist David Paich and session drummer Jeff Porcaro were high school friends with Lukather. They asked Lukather to join in forming their band, Toto, in 1976 when Lukather was nineteen years old. He was a member of Toto from that time until the band split up in 2008. Lukather's reputation as a guitarist and his association with Paich and Porcaro, already established session musicians, allowed him to secure a great deal of session work in the 1970s and 1980s. He is a prolific songwriter, writing or co-writing many songs for Toto and other artists. His career has encompassed hundreds of performances and album appearances with Toto and other well-known musicians. Lukather has been nominated for 12 Grammy awards, and has won five times.

Lukather is known for his acumen in the studio, often recording tracks in one take using minimal sound processing. Although known for using many guitar effects in the studio and on stage, he now frequently disparages such practice, and instead advocates clean tones and minimal studio processing. Lukather plays primarily a signature electric guitar manufactured by Ernie Ball Music Man bearing his nickname, Luke, and equipped with a custom set of EMG pickups. He also plays Ovation Adamas acoustic-electric guitars.