Donald, the world No. 1 and first English player to win the award since its inception in 1990, won twice in 2011. He captured the WGC-Accenture Match Play Championship and the season-ending Children's Miracle Network Hospitals Classic.
It was the last victory in Disney World that secured the money title for Donald. He won the Race to Dubai on the European Tour Sunday and became the first player in history to win the money title on both the PGA and European Tours.
Donald won the scoring average title on the PGA Tour and had the most top 10s with 14. He even had two runner-ups in his steady, spectacular campaign.
"That's a great honor to cap off what has obviously been an amazing year for me," Donald said.
For Bradley, he became the first player since Ben Curtis at the 2003 British Open to win a major in his first major start. Bradley outlasted Jason Dufner to win the PGA Championship at Atlanta Athletic Club.
Bradley collected his first PGA Tour win earlier in 2011 when he toppled Ryan Palmer in a playoff at the Byron Nelson Championship. The nephew of Hall of Famer Pat Bradley is the first rookie since Todd Hamilton seven years ago to win twice.
"I'm thrilled to win the Rookie of the Year," said Bradley. "It's an award you can only win one time, that you only get one chance to win. It's a huge honor."