As a teenager he won national championships on the guitar, mandolin as well as the fiddle. His mentors were Texas fiddler Benny Thomasson and Jazz violinist Stéphane speed dating Grappelli. He has recorded solo albums for Rounder, Warner Bros. Records, Sony, and his own CD line OMAC Records. He has won two Grammy awards, one for his New Nashville Cats album and another for his Appalachian Journey album he did with Yo-Yo Ma and Edgar Meyer. He was named Musician of the Year by the Country Music Association six years in a row (from 1991-1996).One of the most sought after Nashville studio musicians in the 1990s, O’Conner’s violin can be heard on countless hits.
In his career, O’Connor has crossed musical genres, composing, arranging, and recording folk, classical and jazz music. His Fiddle Concerto has received over 200 performances making it one of the most performed concertos written in the last 50 years. He has composed six violin concertos, string quartets, string trios, choral works, solo unaccompanied works and a new Symphony. He has worked and recorded with a wide variety of artists, such as Chet Atkins, James Taylor, Michelle Shocked, Alison Krauss, Bela Fleck, Stéphane Grappelli, The Dixie Dregs and Wynton Marsalis. One of his most popular compositions, Appalachia Waltz (appearing on the album of the same title), has been adopted by Yo-Yo Ma as part of his live performance repertoire. O’Connor hosts an annual fiddle camp (the Mark O’Connor Fiddle Camp) in Tennessee and annual String Camps in San Diego and New York. O’Connor is currently living in New York City.