Yahoo! Sports first reported the lawsuit on Tuesday night.
Wells, who transferred and received a waiver to play at Maryland last season, was kicked out of school in 2012 following an allegation of sexual assault. No charges were filed after Wells was cleared by the grand jury, and Hamilton County (Ohio) prosecutor Joe Deters even told media that the allegation "didn't reach anything close to a standard of proof."
"From the moment the nightmare began, I've been trying to get everyone to understand that I am innocent," Wells said in a statement obtained by ESPN.com. "The supposed leaders at Xavier destroyed my reputation. It needs to make this right. Xavier needs to set the record straight."
A Xavier student claimed that Wells sexually assaulted her on June 7, 2012. Wells said he engaged in consensual sex.
"We have read the complaint and the allegations of wrongdoing are unfounded and cannot be supported," Xavier president, Father Michael Graham, said in a statement to Yahoo! Sports. "The process used by the Xavier University Conduct Board applies to all of our students and is the standard used in American universities. After members of the Conduct Board reached their decision, the matter was considered and upheld in an appeal. The sanction for the offense was expulsion."
Wells was initially denied the waiver by the NCAA to play immediately at Maryland, but the 6-foot-5 sophomore won his appeal and played last season. He led the Terps in scoring at 13.1 points per game.
In the lawsuit, Wells and his attorney claim that the school rushed to judgment following a "false and malicious investigation." They also claim that previous accusations that the school had mishandled allegations lodged against other students for sexual allegations played into the decision to expel Wells.
"Allegations of sexual misconduct should be reviewed and handled with the utmost seriousness," Wells' attorney, Peter R. Ginsburg, said in a statement obtained by ESPN.com. "That does not mean, however, that the rights of the accused should be ignored. Being in a place of higher learning, it is especially disappointing that Father Graham and the other Xavier 'role models' were so grossly irresponsible and uncaring about what they were doing to the reputation -- and life -- of Dez. Xavier's silence for the past year and refusal to acknowledge how it mistreated Dez are inexcusable. This lawsuit is not only for Dez but for anyone who has his or her most basic rights tramped upon."
In the lawsuit, Wells seeks "unspecified damages and to restore Wells' reputation."