The Cajun Classic Open Invitational was a golf tournament on the PGA Tour usually played in late November in the late 1950s and 1960s. It was played at the Oakbourne Country Club in Lafayette, Louisiana. It was first played as the Lafayette Open Invitational in 1958. For many years it was the last tournament on the PGA Tour schedule and attracted players fighting for position on the money list. It lost the last tournament slot on the 1969 schedule and the resulting smaller field caused monetary problems that resulted in the tournament folding.
John Barnum, the only man in the history of the PGA Tour to earn his first win after age 50, won this event in 1962 at age 51. Barnum was also the first player to win on Tour using a Ping putter.