In the NBA, the arc is 23 feet, 9 inches (7.24 m) from the basket, but near the sidelines, three-point line is straight and parallel to the sideline in order to allow room between the three-point line and the sideline. Hence, the distance varies near the sidelines; it is 22 feet (6.72 m) at its closest point in the corner. http://en.wikipedia.org/wiki/Three-point_field_goal

23 feet 9 inches. Edit: That's in the center. 22 feet in the corners.

The NBA line is 23 feet 9 inches. The NCAA will change that this year. The 3 point shot was introduced by the upstart ABL in 1961 (the league only survived a couple of years) and was brought back by the ABA in 1971 (along with the 30 second shot clock and the dunk) and adopted by the NBA after they merged in 1979-80. The NCAA allowed the Southeast Conference to experiment with 3-pointers in 1980-81 and the rest of the College conferences followed suit within the next two seasons. In the year of the 20-year anniversary, the NCAA men's basketball rules committee decided the 3 point line needed a makeover. So, beginning with the 2008-09 season,the line will move back a full foot to 20 feet, 9 inches. The committee chose, however, not to expand the size of the lane. The women's committee decided to keep its line at 19 feet, 9 inches, meaning there will be two distances and, possibly, two different lines on courts that men's and women's programs share. So, the line will now be three inches longer than the international line, giving high school players the need to adjust to an international line, a college line and, perhaps, in some cases, to the NBA line of 23 feet, 9 inches.