Luther Johnson (born April 11, 1939, Itta Bena, Mississippi) is an American Chicago blues singer and guitarist, who performs under the name Luther “Guitar Junior” Johnson. He is not to be confused with Luther “Snake Boy” Johnson, Luther “Houserocker” Johnson, from Atlanta; or Lonnie “Guitar Junior” Brooks.

Johnson moved to Chicago with his family in 1955. During the 1960s, he performed with Magic Sam. He performed in Muddy Waters‘s band from 1972 to 1980. In 1980, four of his songs were included in an anthology released by Alligator Records. That same year he appeared as a member of the Legendary Blues Band, backing John Lee Hooker in the movie The Blues Brothers.