Palmer turned professional in 2000. He played on the mini-tours (Tight Lies Tour and
Hooters Tour) from 2000 to 2002; he won several tournaments on the Tight Lies Tour and topped the money list in 2002. Palmer came close to winning a fourth career title at his hometown event the
HP Byron Nelson Championship in
Texas in May 2011. Palmer entered the final round leading by one stroke, but as the final round progressed in windy conditions he had to hole a birdie putt on the last to enter a playoff with
Keegan Bradley. On the first playoff hole, the 18th, both players hit their tee shots out to the right amongst the trees. Bradley played his approach to just short of the green whereas Palmer hooked his approach shot into the water. Palmer pitched up close to the hole and made bogey but Bradley was able to win with a pitch and putt par. In March 2014, Palmer lost another sudden-death playoff at the
Honda Classic, after missing a five footer for what would have been the win on the 18th green in regulation play. He entered the four-man playoff, having been the only one to shoot an under-par final round. However, in the playoff, after missing the green in two, he could not get up and down, leaving
Russell Henley to hole from three feet for victory. This was Palmer's second runner-up finish of the year, after finishing two shots behind
Patrick Reed at the
Humana Challenge in January 2014. Palmer started the 2017–18 season on a Major Medical Extension under the family crisis provision as his wife underwent chemotherapy treatment. He met the terms of his medical extension at the
CareerBuilder Challenge, then lost in a sudden-death playoff at the
Farmers Insurance Open the following week. Trying to end an eight-year winless drought on tour, Palmer, playing in the final group, birdied the 72nd hole to join a playoff with
Jason Day and
Alex Norén. However, Palmer was eliminated at the first extra hole, as he could only make par to the others' birdies on the 18th. In April 2019, Palmer won the
Zurich Classic with teammate
Jon Rahm. ==Professional wins (9)==