He continued his amateur success by becoming the first amateur to win the Chicago Open in 2000. Donald turned professional in 2001, joining the PGA Tour in 2002, where he quickly secured his maiden title at the Southern Farm Bureau Classic in November 2002. His early professional career also saw victories on the European Tour, including the Scandinavian Masters and the Omega European Masters, both in 2004, and a win at the WGC-World Cup with Paul Casey in 2004. Demonstrating consistent excellence, Donald accumulated 5 PGA Tour wins and 7 European Tour wins throughout his career.
Beyond his individual triumphs, Donald played a pivotal role as a key member of multiple victorious European Ryder Cup teams in 2004, 2006, 2010, and 2012, significantly contributing to their triumphs. Recognizing his profound contributions to the sport, he was appointed a Member of the Order of the British Empire (MBE) in 2012. Donald later transitioned into a celebrated leadership role, captaining the European team to a resounding victory in the 2023 Ryder Cup. He replicated this remarkable success by leading the European team to another Ryder Cup victory in 2025, an extraordinary achievement that positioned him as one of only two Ryder Cup Captains in history to secure both home and away victories.