After graduating from high school, Plumlee continued his football career at the collegiate level, playing as a quarterback for the University of Mississippi, also known as Ole Miss. During his time at Ole Miss, Plumlee demonstrated his talents as a dual-threat quarterback, showcasing his ability to pass and run effectively on the field. His dynamic playing style and athleticism garnered attention from NFL scouts, leading to his selection by the Pittsburgh Steelers in the 2023 NFL Draft.