Karl Kirk (5 April 1890 in Sønder Nærå, Denmark – 6 March 1955 in Aarhus, Denmark) was a Danish gymnast who competed in the 1912 Summer Olympics. He was part of the Danish team, which won the silver medal in the gymnastics men's team, Swedish system event.
He worked as a teacher and later principal at Eriksminde Efterskole from 1916 until his death in 1955.