Stidham, who played for Stephenville in Texas, is the No. 4 quarterback recruit and No. 57 overall recruit in the class of 2015, according to Rivals.
He is the 14th member of Baylor's recruiting class, which is ranked No. 39 by Rivals. Coach Art Briles' Bears went 11-1 and were co-champions of the Big 12. They will play Michigan State in the Cotton Bowl on New Year's Day.
Stidham received offers from a number of upper echelon college football programs, including Alabama, Auburn, Ohio State and Oregon. Several of Texas Tech's in-state rivals -- Texas, Texas A&M, and TCU -- also offered Stidham.
Stidham had signed a financial agreement with Texas Tech in August and planned on enrolling early at the school.
The Red Raiders finished 4-8 this season, the first time the team had failed to finish with at least five wins since 1990.
- Stanley Kay & Paul Palladino