|Full name||John O. Barnum|
|Born||October 6, 1911|
|Died||October 30, 1996(aged 85)|
|Former tour(s)||PGA Tour|
|Number of wins by tour|
|Best results in major championships|
|PGA Championship||T16: 1958|
|U.S. Open||T31: 1950|
|The Open Championship||DNP|
Barnum is notable for two significant milestones in golf. He was the second golfer (after Jim Barnes), and one of only seven, ever to win a PGA Tour event after turning 50, and the only player to win his first PGA Tour event past the age of 50. The other significant milestone is that Barnum was the first player to win a PGA Tour event using a Ping putter. His best finish in a major was T-16 at the 1958 PGA Championship.
Barnum won five Michigan PGA Senior titles, and was runner-up three times in the PGA Seniors' Championship (1963, 1964, 1966). He was inducted into the Grand Rapids Sports Hall of Fame in 1972, and elected to the Michigan Golf Hall of Fame in 1984.
Amateur wins (2)
- 1939 Mexican Amateur
- 1940 Mexican Amateur
PGA Tour wins (1)
|No.||Date||Tournament||Winning score||Margin of victory||Runner(s)-up|
|1||Nov 11, 1962||Cajun Classic Open Invitational||–14 (68-70-63-69=270)||6 strokes||Gay Brewer|
- 1950 Michigan Open
- 1957 Michigan PGA Championship
- 1958 Michigan Open, Michigan PGA Championship
- 1960 Michigan Open
- 1961 Michigan Open, Michigan PGA Championship
- Five Michigan PGA Senior Championships
- "Oldest PGA Tour winners". Retrieved 2008-01-10.
- Dear, Tony. "Keeping it in the Family". Retrieved 2008-01-10.
- "Golf Major Championships". Retrieved 2008-01-11.
- "Biographical information from Michigan Golf Foundation". Archived from the original on 2007-10-10. Retrieved 2008-01-10.
- "Grand Rapids Sports Hall of Fame". Archived from the original on 2013-01-03. Retrieved 2008-01-10.