Atlanta's Horford was the only unanimous choice with 58 votes, followed by Seattle's Durant with 57 in balloting by the league's head coaches.
Horford ranked first among rookies in double-doubles (25) and rebounds (9.7), helping the Hawks end the league's longest postseason drought with their first playoff berth since 1999.
The 6-foot-9 Durant led the SuperSonics with 20.3 points per game, 7.6 more than any other rookie. He was the only first-year player to lead his team in five categories -- points, blocks, steals, free throws made and free throw percentage. Durant blocked more shots than any other guard in the league (75).