The match, which will be played on Sunday 6 August at the Aviva Stadium, will provide a final opportunity for Erik ten Hag to finetune his first-team squad before the season opener, and a rare chance for fans in Dublin to see United play on Irish soil.
It will be the third time that United have played at the 51,700-capacity arena, with a 7-1 win over a League of Ireland XI in the 2010 opening game, followed by a 2-1 victory over Italian side Sampdoria six years ago.
United last faced Athletic Club in the 2012 Europa League and, before that, in the 1957 European Cup – our first season in European competition.