Kuruppu Arachchige Karunaratne (or K.A. Karunaratne; 29 April 1960 – 6 April 2008) was a Sri Lankan long-distance runner who specialized in the marathon event. As a runner he won 1990 Singapore Marathon in a time of 2:21:10, competed at the 1992 Summer Olympics and the 1993 World Championships.