Jail documents show John Attanasio, 60, was booked into the Collin County jail after he was arrested at a Frisco hotel on Saturday night.
The Texas Department of Public Safety said the arrest was part of an ongoing investigation and undercover officers apprehended Attanasio.
Court documents said Attanasio responded to an ad on Backpage.com and offered to pay the undercover officer $100 in exchange for specific sexual acts.
Attanasio was released on $500 bond.
He served as dean of SMU's law school from 1988 to 2013 and still holds a teaching position at the school.
SMU is not commenting on the police investigation.
Attanasio is married with children. FOX 4 called his home Monday evening, but got no answer.