His third year on Tour included three victories (Bass Pro Shops Legends of Golf at Big Cedar Lodge, KitchenAid Senior PGA Championship, The Ally Challenge) and two additional finishes in the top 10 resulting in over $1.5 million in winnings. Competed in the Charles Schwab Cup Championship for the third consecutive year, finishing No. 10 in the standings.

Broadhurst aced the 14th hole at Omni Tucson National's Catalina Course during the first round of the Cologuard Classic. It was his first career hole-in-one on PGA TOUR Champions. He went on to finish T18.

Broadhurst teamed up with Kirk Triplett to win the Bass Pro Shops Legends of Golf at Big Cedar Lodge in a playoff over Bernhard Langer and Tom Lehman. As a team, Broadhurst/Triplett went bogey-free en route to a 24-under total, and they won after Triplett holed a bunker shot for birdie on the first extra hole. The win was Broadhurst's third of his career and first since the 2016 PURE Insurance Championship.

Broadhurst shot a final-round 63 and turned a two-shot deficit into a four-shot victory at the KitchenAid Senior PGA Championship. The win was his second senior major and fourth victory on PGA TOUR Champions, and he became the fifth player to lead the Charles Schwab Cup during the 2018 season. Broadhurst's total of 265 matched the lowest 72-hole total in the tournament's 79-year history, and his final-round 63 was the best finish by a winner in the tournament history.

Carded a pair of 69s over the weekend to finish 1-under-par 279 for T5 at the U.S. Senior Open.

Broadhurst won in Michigan for the second time this season, as a final-round 66 gave him a 15-under total and a two-shot victory at the inaugural Ally Challenge, held at Warwick Hills Golf & Country Club. He started the final round one shot off the lead, and eight players held at least a share of the lead on Sunday. Broadhurst was one of eight players in the field that did not play the Buick Open on the PGA TOUR.