James P. Johnson (born James Price Johnson, also known as Jimmy Johnson; February 1, 1894 – November 17, 1955) was an American pianist and composer. A pioneer of the stride style of jazz piano, he was one of the most important pianists who bridged the ragtime and jazz eras, and, with Jelly Roll Morton, one of the two most important catalysts in the evolution of ragtime piano into jazz. As such, he was a model for Count Basie, Duke Ellington, Art Tatum, and Fats Waller.

Johnson composed many hit tunes including the theme song of the Roaring Twenties, "Charleston" and "If I Could be With You One Hour Tonight" and remained the acknowledged king of New York jazz pianists through most of the 1930s. Johnson's artistry, his significance in the subsequent development of jazz piano, and his large contribution to American musical theatre, are often overlooked, and as such, he has been referred to by Reed College musicologist David Schiff, as "The Invisible Pianist".