Walter Armstrong, III (born June 19, 1945) is an American professional golfer who played on the PGA Tour during the 1970s and 1980s.

His best finishes were a trio of second places: a tie for second at the 1974 Sahara Invitational, second at the 1975 Pensacola Open, and a second-place tie at the 1977 Western Open.

His best finish in a major was a fifth-place tie at the 1978 Masters Tournament.

His 280 total in 1978 was a record low for a first-time Masters participant.

In his post-playing career, Armstrong is a golf instructor and author.