Nils Olav Fjeldheim (born 18 April 1977, Tysvær) is a Norwegian sprint canoer and marathon canoeist who competed from 1998 to 2004. Competing in two Summer Olympics, he won a bronze in the K-2 1000 m event at Athens in 2004.
He won a complete set of medals at the ICF Canoe Sprint World Championships with a gold (K-2 1000 m: 2001), a silver (K-2 1000 m: 2002), and a bronze (K-4 200 m: 1998). Fjeldheim retired from international racing in 2005. He lives in Tysvær, Norway.