David J. Mayernik (born June 15, 1952) is a former Democratic member of the Pennsylvania House of Representatives. He is a 1970 graduate of North Hills High School. He earned an A.A. from the Allegheny Community College in 1972 and a B.A. from the University of Pittsburgh in 1974. In 1975, he graduated from the Allegheny County Police Academy. He earned an M.A. from University of Pittsburgh in 1981 and a J.D. from Widener University School of Law in 1993. In a 2002 PoliticsPA Feature story designating politicians with yearbook superlatives, he was named the "Toughest to Work For."