Lowry elected to turn professional the week after his Irish Open triumph, meaning that he would miss out on the opportunity to play in the Walker Cup in September 2009. He made his professional début on 28 May at the European Open, where he shot 78 in the first round to end the opening day almost at the back of the field, and went on to miss the cut following a second round 73.
Lowry missed the first three cuts of his professional career, but had his first payday on 5 July, when he finished 50th at the Open de France ALSTOM. He had his best professional result in November 2009, when he finished 3rd in the Dunlop Phoenix Tournament in Japan. In January 2010, Lowry finished in fourth place in the Abu Dhabi Golf Championship, moving him into the top-100 of the Official World Golf Ranking.
THE PLAYERS Championship: After beginning the final round of THE PLAYERS Championship three strokes off the lead, at 7-under 209, played his last six holes in 6-under to post a 6-under 66 and join a three-hole aggregate playoff with 2008 PLAYERS champion Sergio Garcia and Kevin Kisner. Finished birdie-par-birdie-eagle-birdie-birdie on Nos. 13-18 in regulation. Played Nos. 15-18 in a 5-under total of 11 strokes. The four-hole score of 11 set a new single-round low for the final four holes at TPC Sawgrass. Previously, seven players had finished with a score of 12 on the final four holes. When Garcia was eliminated after the aggregate playoff, Fowler and Kisner returned to the famed, par-3 17th for sudden death. Fowler converted a 4-foot, 8-inch putt for birdie to claim the title. Before his back-nine charge, his mother had made her way to the airport to leave town. A text message alerting her to her son's rally resulted in her immediate return to TPC Sawgrass in time to witness the win. With the victory, moved to ninth in the Official World Golf Ranking and No. 7 in The Presidents Cup standings.
Hyundai Tournament of Champions: Finished T6 in a Monday-start-Tuesday-finish event, the season-opening, 54-hole Hyundai Tournament of Champions. The event "started" twice during the regularly scheduled first round Friday and later Sunday, but both times PGA TOUR rules staff halted play due to unplayable windy conditions and subsequently voided all scores that had taken place. As the first player off the tee, he ended up hitting three "opening" shots of the season.