The 6-foot-9 inch native of Washington captured the honor Thursday by a huge margin over forward Al Horford of Atlanta in the poll of 125 writers. Durant got 90 first-place votes and a total of 545 points.
"I didn't think I was going to win it," the 19-year-old Durant told NBA.com. "It's a great honor for me and the team, so I'm happy with it. It's a stepping stone to help me become a better player for next year."
Durant led all rookies with 20.3 points, 4.4 rebounds and 2.4 assists per game in 80 contests.
He is the first Seattle player ever to capture the rookie award.
Horford got 30 first-place votes and 390 points. Forward Luis Scola of Houston finished third with 146 points.