Klára Rajnai (born November 21, 1953) is a Hungarian sprint canoer who competed in the mid to late 1970s. She won two medals at the 1976 Summer Olympics in Montreal with a silver in the K-2 500 m and a bronze in the K-1 500 m events.
Rajnai also won two bronze medals at the ICF Canoe Sprint World Championships with one in the K-1 500 m (1979) and one in the K-4 500 m (1975 event.