John Alexander Jacobs (born March 18, 1945) is an American professional golfer who played on the PGA Tour and currently plays on the Champions Tour. Jacobs is the younger brother of professional golfer Tommy Jacobs.

Jacobs was born in Los Angeles, California. He turned professional in 1967. He played on the PGA Tour from 1968–1980. He never won an official PGA Tour event; his best showings were three 2nd place finishes.

After reaching the age of 50 in 1995, Jacobs began play on the Champions Tour; his level of success has been dramatically greater than during his regular career. His accomplishments as a senior include a major championship and more than 70 top-10 finishes.