Born in Los Angeles, California on January 11, 1952, Ritenour took up the guitar when he was eight years old, and decided to make music his career when he was 12. Ritenour's parents were supportive of his ambitions, and arranged for him to study with some of the best guitar teachers in Southern California. At 15, he joined a rock band called the Esquires, and when John Phillips heard Ritenour at work, he invited him to play on an upcoming session by the Mamas and the Papas; it was the first record date for the 16-year-old guitarist. While Ritenour's tastes were eclectic and he worked with a number of rock and soul artists, he had a special passion for jazz, citing Wes Montgomery as a key influence, and within a few years he was playing prestigious gigs with the likes of Lena Horne and Tony Bennett. Ritenour took time off from his career to attend the University of Southern California, where he studied classical guitar under Christopher Parkening, but he returned to work after two-and-a-half years. By the mid-'70s, Ritenour was one of the top session musicians in Los Angeles, lending his talents to albums by the likes of Steely Dan, Pink Floyd, Barbra Streisand, Aretha Franklin, Carly Simon, Bobby "Blue" Bland, Natalie Cole, the Bee Gees, and Quincy Jones, as well as jazz projects with Sonny Rollins, Dizzy Gillespie, Alphonso Johnson, and Stanley Turrentine. Ritenour also had a keen interest in Brazilian and Latin sounds; he toured with Sergio Mendes in 1973, and recorded with Flora Purim, Gato Barbieri, and Paulinho Da Costa.

In 1976, Ritenour stepped into the spotlight with his first solo album, First Course, a polished jazz-pop effort released by Epic Records. After cutting four albums for Epic, Ritenour moved to the Elektra-distributed Discovery imprint with 1978's The Captain's Journey, the first of seven albums he'd cut for Elektra and its offshoots. In 1985, Ritenour recorded Harlequin with pianist Dave Grusin; the two would become frequent collaborators, and Grusin's GRP label would release the lion's share of Ritenour's solo work well into the 21st century. In 1990, Ritenour played on the sessions for Bob James' album Grand Piano Canyon, along with bassist Nathan East and drummer Harvey Mason; the musicians enjoyed working together so much they formed a group, and Ritenour, James, East, and Mason released their first album as Fourplay in 1991. The Fourplay album was a significant commercial success, and Ritenour would cut two more LPs with the combo, 1993's Between the Sheets and 1994's Elixir, before exiting the group, with Larry Carlton taking his place. While Ritenour maintained a busy schedule with his solo work and his projects with Dave Grusin and Bob James, he continued to do frequent session work (it has been estimated Ritenour has played on 3,000 different recordings) as well as performing live around the world. In 2005, Ritenour changed labels, releasing his album Overtime with Concord Records, and in 2010, he issued Six String Theory, in which he collaborated with a diverse range of fellow guitarists, including B.B. King, George Benson, Keb' Mo', Pat Martino, and many more. 2012 found Ritenour releasing another collaborative effort, Rhythm Sessions, which included a number of stellar guest artists (Dave Grusin, Stanley Clarke, George Duke, Chick Corea, and Patrice Rushen among them) along with the winners of a musical talent competition Ritenour organized in 2010. In 2015, Ritenour returned with A Twist of Rit, which featured new songs, plus reworkings of cuts off his 1975 debut, First Course, and 1981 offering, Rit. ~ Mark Deming