Billings was drafted out of Michigan State University by the Washington Senators in the 25th round of the 1965 Major League Baseball draft. He played as an outfielder and occasional third baseman in the Senators' minor league system for four years before making his major league debut at the age of 25 as a pinch hitter on September 11, 1968. Billings had his first appearance as a starting player on September 20, as a left fielder in a game against the Detroit Tigers.