The two north-west rivals will go head-to-head in Miami after both did enough to top their respective groups in the preseason tournament in the U.S.
Liverpool's qualification for the match in Miami was confirmed after Manchester City's defeat on penalties to Olympiakos, while the Red Devils' win over Real Madrid proved enough for them to also go through.
The match will mark a first chance for Louis van Gaal to secure a victory over his new team's oldest rivals while also picking up some silverware following an impressive first month in charge.
Van Gaal has led the Old Trafford outfit to wins over Madrid and Roma while victory on penalties over Inter proved to be the defining result of its group campaign.
Brendan Rodgers' side, meanwhile, was victorious against Olympiakos in its opening match before beating Manchester City on penalties. The Reds complete their opening fixtures against AC Milan on Saturday evening.
The final will kick off at 8 p.m. ET on Monday evening.