North Carolina finished the season with a 23-8 record, a No. 10 national ranking in the final Associated Press poll after being unranked in the preseason and a second place finish in the Atlantic Coast Conference after being picked to finish sixth in the preseason in the ACC.
This is the second time in his career that Williams has been named coach of the year by the Basketball Writers and is the first coach in the 50-year history of the USBWA to receive the honors at two different programs. He was selected coach of the year at Kansas in 1990.
The USBWA will present Williams with the association's Henry Iba Coach of the Year Award at this year's NCAA Final Four on March 31 in Indianapolis.
The 6-9, 235-pound Hansbrough, from Poplar Bluff, Mo., averaged 18.9 points and 7.8 rebounds for North Carolina to become the first North Carolina freshman to lead the Tar Heels in both categories.
Hansbrough led all freshmen in the nation with a .570 field goal shooting percentage and was the first freshman to be a unanimous all-Atlantic Coast Conference first-team selection.