Irving Conrad Ashby (December 29, 1920 – April 22, 1987) was an American jazz guitarist.

Ashby was born in Somerville, Massachusetts and started playing guitar when he was nine. His career started in 1940 when he became a member of Lionel Hampton's band, and he played on Hampton's hit "Flying Home". In 1947, he took over for Oscar Moore in the Nat King Cole Trio.

He then briefly replaced Charlie Smith, a drummer, in the Oscar Peterson Trio, producing a line-up (piano, guitar, bass) similar to the Cole Trio's; the substitution of a guitarist for a drummer continued until 1958. After leaving the Peterson Trio, Ashby concentrated on session work, which included recording with Norman Granz, Sheb Wooley, LaVern Baker, Howard Roberts, B.B. King, Louis Jordan, and Pat Boone. In addition to guitar, Ashby played the upright bass. Ashby died in April 1987 in Perris, California, at the age of 66.