Dorsey, a projected first round NFL Draft pick, earned First-Team All-America honors as a junior in 2006 after recording 64 tackles, 8.5 tackles for losses and three sacks for the third-ranked Tigers.
Dorsey anchored an LSU defensive that ranked No. 3 in the nation in total defense (242.8 yards per game) and No. 4 in scoring defense (12.6 points per game). The Tigers also allowed only 93 yards rushing a contest, a figure that ranked No. 2 in the Southeastern Conference.
Dorsey twice earned the SEC Defensive Lineman of the Week award in 2006. He was also a First-Team All-SEC selection in what was his first year as a starter for the Tigers.
"LSU is a great place and I feel like coming back to school for one more season is the best decision for me," Dorsey said. "I still enjoy being in college and playing college football. This is a great community and I wanted to have the opportunity to experience playing football at LSU for one more season.
"I feel good about my decision. I sought out advice from other players and my coaches. I'm just looking forward to getting ready for next season and being a leader on this team."
In three years with the Tigers, Dorsey has recorded 110 tackles, 14.5 tackles for losses and six sacks. The return of Dorsey gives the Tigers eight returning starters on defense, including three defensive linemen and all three linebackers.
"We are especially pleased with Glenn's decision to return to LSU for another year," LSU coach Les Miles said. "Anytime a player postpones millions of dollars to return to school for another year, it's a very personal decision. We were going to support Glenn in whatever decision he made.
"Glenn is a class act and a tremendous player on the field and an outstanding person off the field. He's a team leader and we look forward to having him around for another year."
Dorsey's decision came less than a week after LSU junior quarterback JaMarcus Russell opted to forgo his senior season to enter the NFL Draft.