Joachim Mattern (born 2 May 1948 in Beeskow) is an East German sprint canoeist who competed in the 1970s. Competing in two Summer Olympics, he won two medals at Montreal in 1976 with a gold in the K-2 500 m and silver in the K-2 1000 m events.

Mattern also won five medals at the ICF Canoe Sprint World Championships with a gold (K-2 500 m: 1977), two silvers (K-2 1000 m: 1977, K-4 1000 m: 1970), and two bronzes (K-2 1000 m: 1970, 1973).

• ICF medalists for Olympic and World Championships – Part 1: flatwater (now sprint): 1936–2007 at the Wayback Machine (archived 5 January 2010)
• ICF medalists for Olympic and World Championships – Part 2: rest of flatwater (now sprint) and remaining canoeing disciplines: 1936–2007 at WebCite (archived 9 November 2009)
• Evans, Hilary; Gjerde, Arild; Heijmans, Jeroen; Mallon, Bill; et al. "Joachim Mattern". Olympics at Sports-Reference.com. Sports Reference LLC. Archived from the original on 18 March 2009.