The oldest golfer to make the cut in a men's major championship was 67 years old at the time.
The golfer was Sam Snead. The major was the 1979 PGA Championship. Snead was 67 years, 2 months, 7 days old at the time he made the cut.
Snead finished 42nd in the event, shooting 73-71-71-73 for an 8-over total of 288.
Source: PGA Tour
