The Premier League champions agreed the fixture as part of a long-standing arrangement between Sir Alex Ferguson and County’s director of football George Adams, his one-time youth coach at Aberdeen.
It is understood United are to split their first team squad between friendlies and keep some established players on British soil. County have received strong hints there will be crowd-pullers among the travelling party heading to the Highlands.
The occasion will mark the £700,000 final phase of redevelopment at the Global Energy Stadium, with the opening of 650 new East Stand seats and newly-lain turf.
The English giants made their one previous visit to the old Victoria Park in August 1973 when Scot Tommy Docherty was boss. A thrilled County chairman Roy MacGregor said: “This is a great coup for the club and one that was promised us a while ago. Our director of football George Adams was behind it and Sir Alex himself phoned to put the final arrangements in place.”