Lee Oskar Harmonicas was founded in 1983 by harmonica player Lee Oskar — a founding member of the funk band War — in partnership with Tombo Manufacturing of Japan, a harmonica maker with roots going back to 1917. The company is based in Everett, Washington, and its instruments are manufactured by Tombo to Lee Oskar's specifications.

The brand is known for its diatonic harmonicas built around a system of interchangeable reed plates, combs, and cover plates, which lets players replace worn parts rather than the whole instrument. The lineup centers on four models in the same body design: the Major Diatonic for blues, rock, country, and folk; the Melody Maker, retuned to favor major-scale melodies and second-position playing; the Natural Minor, voiced for minor blues and rock; and the Harmonic Minor, aimed at klezmer, Eastern European, and other world music styles.

Lee Oskar harmonicas are widely used by blues, rock, and pop harmonica players, and the alternate-tuning models in particular are credited with making non-blues styles more accessible on a standard 10-hole diatonic.

Lee Oskar has 14 products cataloged on Equipboard, including Harmonicas. Their gear is featured by 13 artists, with the strongest followings in Rock, Folk, World, & Country, and Blues. Notable users include Mick Jagger, Ozzy Osbourne, and Roger Daltrey.