The Republic of Ireland international joined United in the summer of 2021, and has made 28 appearances in red since her debut in the 2-0 home over Reading in September 2021.
Most notably last season, Aoife returned from a long-term injury to put on a Player of the Match performance when helping to secure a 1-0 home win over Arsenal in the WSL.
Aoife Mannion said:
“I'm so delighted to be staying here at United. It was an easy choice for me and I'm really pleased to continue this journey and see where we can go over the next few seasons.