Eugene Franklin "Lefty" Hayden (April 14, 1935 – June 13, 2003) was an American professional baseball player who had a brief career in Major League Baseball as a relief pitcher for the Cincinnati Redlegs in 1958. The native of San Francisco, listed at 6 feet 2 inches (1.88 m) and 175 pounds (79 kg), threw and batted left-handed.