The move, which came a day after Kavis Reed was named special teams co-ordinator, completes the top level of the CFL club's coaching staff under head coach Tom Higgins and defensive co-ordinator and assistant head coach Noel Thorpe.
Schonert and Jeff Garcia, both former quarterbacks, joined the Alouettes in July to assist inexperienced offensive co-ordinator Ryan Dinwiddie. They helped turn around a team that started the 2014 campaign at 1-7 and ended at 9-9.
Dinwiddie remains on the staff as an offensive assistant along with former quarterback Anthony Calvillo. Garcia left after the season.
Schonert's official title last season was receivers coach, although he also had a hand in game planning. He helped Duron Carter and S.J. Green turn around slow starts and have productive years. Carter was named a league all-star with 1,030 receiving yards while Green starred in the playoffs.
Schonert reportedly looked at NFL opportunities before opting to return.
"Turk played an important role in last season's turnaround and we are thrilled to have him back with us, as this will allow us to have some consistency on offence," Higgins said in a statement. "He has experience and is well liked by the players.
"We now have all the pieces of the puzzle in place and look forward to getting ready for what should be a promising season."
Last season, it took until late in the winter for the coaching staff to be settled, and then offensive co-ordinator Rick Worman was fired during training camp.
Schonert was a quarterback for nine NFL seasons from 1981 to 1989. He later held coaching jobs with Tampa Bay, Buffalo, Carolina, the New York Giants and New Orleans.