James Oscar Smith (December 8, 1925 – February 8, 2005) was an American jazz musician whose albums often appeared on Billboard magazine charts. He helped popularize the Hammond B-3 organ, creating a link between jazz and 1960s soul music.

In 2005, Smith was awarded the NEA Jazz Masters Award from the National Endowment for the Arts, the highest honor that America bestows upon jazz musicians.

There is confusion about Smith’s birth year, with sources citing either 1925 or 1928. Born James Oscar Smith in Norristown, Pennsylvania, he joined his father doing a song-and-dance routine in clubs at the age of six. He began teaching himself to play the piano. When he was nine, Smith won a Philadelphia radio talent contest as a boogie-woogie pianist. After a period in the U.S. Navy, he began furthering his musical education in 1948, with a year at Royal Hamilton College of Music, then the Leo Ornstein School of Music in Philadelphia in 1949. He began exploring the Hammond organ in 1951. From 1951 to 1954, he played piano, then organ in Philly R&B bands like Don Gardner and the Sonotones. He switched to organ permanently in 1954 after hearing Wild Bill Davis.