Liverpool's qualification for the match in Miami was confirmed after Manchester City's defeat on penalties to Olympiakos while United's impressive 3-1 win over Real Madrid proved enough for them to also go through.
The match will mark a first chance for Louis van Gaal to square up to his new team's oldest rivals while also giving him the opportunity to pick up some silverware following an impressive first month in charge of the club.
Van Gaal has led the Old Trafford outfit to wins over Serie A sides Inter and Roma during their International Champions Cup campaign, while two goals from Ashley Young and one from Javier Hernandez ensured they would defeat Real Madrid in front of 109,000 plus fans in Michigan.
Brendan Rodgers's side, meanwhile, were victorious against Olympiakos in their opening match of the ICC before beating Manchester City on penalties after an entertaining 2-2 draw during normal time.
The Reds followed that up with a 2-0 victory over AC Milan in their final group game, with goals from Joe Allen and Suso doing the damage despite a missed penalty from summer signing Rickie Lambert.
The final will kick-off at 01:00 BST on Tuesday August 5 and you can follow the action LIVE right here on Goal!