It was Los Blancos' 12th victory in the competition and sets up yet another date in the Super Cup, which pits the Champions League holders with their Europa League counterparts.
United won the Europa League - and booked their place in the 2017-18 Champions League group stage - by seeing off Ajax in May. Paul Pogba and Henrikh Mkhitaryan scored in their 2-0 win in Stockholm.
It will be the first meeting between the two clubs since the 2012-13 season, when Madrid knocked United out of the Champions League in controversial circumstances after Nani was sent off in the second leg at Old Trafford.
WHEN IS THE UEFA SUPER CUP?
The 2017 UEFA Super Cup will be played on Tuesday, August 8 at 20:45 CEST / 19:45 BST. It will take place at the Philip II Arena in Skopje, Macedonia, which holds 33,460 fans.
Skopje is a four-hour flight from Manchester and the Premier League season will start the weekend immediately following the Super Cup, so Jose Mourinho's 2017-18 campaign will begin as the 2016-17 one ended - with travelling and fixture congestion.
WHO WON THE LAST SUPER CUP?
Real Madrid are looking to defend the Super Cup having beaten Sevilla to win it last year. Jorge Sampaoli's side were leading 2-1 until a last-gasp Sergio Ramos equaliser, with Dani Carvajal grabbing the winner in extra time.
Madrid also beat Sevilla to win it in 2014, and have claimed the trophy three times in total. The first came back in 2002, when they beat Feyenoord.
United have only won the Super Cup once - back in 1991, when they played European champions Red Star Belgrade as Cup Winners' Cup champions. They lost to Lazio in 1999 and Zenit in 2008 after winning the Champions League.