Mills played 13 games, primarily on special teams this season.
Dennis-Sutton is the fifth Nittany Lion to announce his return for the 2025 season, along with Drew Allar, Zakee Wheatley, Zane Durant, Nick Singleton, and Kaytron Allen.
Allen finished his Penn State career with 822 yards on the ground during the 2024 regular season.
Singleton recorded his second 1,000 yard season in his third year with the Nittany Lions.
The team remains undefeated in conference play to start the new year.
Penn State will now search for its third defensive coordinator in as many seasons.