Paulus, who attends Christian Brothers Academy in Syracuse, N.Y., said he chose North Carolina over USC.
"Coach (John) Bunting was extremely happy," Paulus said. "He said 'I'm a very, very happy head coach right now. I'm grinning ear to ear.' "
A four-star prospect, according to Scout.com, Paulus also made a phone call to Southern Cal head coach Pete Carroll to inform him of the decision.
"Coach Carroll was very classy; he said 'You're unbelievable, we wish we could have had you - North Carolina is really lucky because you're going to be very good,' " Paulus said.
In addition to finalists UNC and USC, Paulus received more than 30 scholarship offers, which included Tennessee, LSU, Miami and Alabama. And although Signing Day 2007 is nine months away, Paulus said his commitment is very solid.
"I'm not even interested in any other schools," he said.
Paulus, the younger brother of Duke point guard Greg Paulus, gave several key reasons for choosing the Tar Heels.
"The overall atmosphere, the coaches, my level of comfort there," he explained. "With coach Frank Cignetti I feel like me and him together can do some big things in the ACC at North Carolina."
As a junior, the 6-foot-5, 208-pound quarterback led Christian Brothers to a 7-2 record. Paulus passed for more than 2,100 yards and 20 touchdowns with a 59 completion percentage during the season.
But as good as he is now, the coaches that recruited him said his potential is off the charts. And Paulus was looking for the right school to help him realize that potential.
"That was a big part of it, too — who could develop me because I'm so raw. (Coach Cignetti) will be able to develop me," he said.
"Everyone talks about my potential and upside and I feel the same way about North Carolina. With the players there, the sky is the limit. I'm going to go up there, get after it and win some ACC championships."