Steinhardt made his debut with the Los Angeles Philharmonic Orchestra at the age of 14.
He studied at the Curtis Institute of Music in Philadelphia with Ivan Galamian and later in Switzerland with Joseph Szigeti and Toscha Seidel.
He lives in Santa Fe, New Mexico, and is the author of two books; Indivisible by Four: A String Quartet in Pursuit of Harmony, an account of his life in the Guarneri String Quartet, and Violin Dreams, an autobiography about his life and experiences as a violinist.
He appeared as himself in the 1999 film Music of the Heart, starring Meryl Streep and also featuring violinists Isaac Stern and Itzhak Perlman.
His wife, Dorothea von Haeften, is a supporting character in the film, played by Jane Leeves.