Jan Clifford Christiansen (born 8 April 1941) is a Norwegian former football player and coach.
He played for Rosenborg BK in Trondheim from 1966 to 1975, earning three league titles and one cup championship.
Christiansen was capped 13 times for Norway national football team.
Jan Christiansen came to Trondheim in 1965 as student at the Norwegian Institute of Technology.
Prior to this, he had played football for his hometown team Enebakk IF and in the second division for Lillestrøm.