As part of his role, the Scot, who netted 237 goals in 404 Reds appearances between 1962 and 1973, will attend various events and functions on behalf of the club, promoting the work it does within the community and with its partners and sharing anecdotes from his time at Old Trafford.
Speaking about the appointment, Law said he was honoured to join Sir Bobby Charlton, Bryan Robson, Gary Neville, Andrew Cole and Peter Schmeichel as an official United ambassador.
"I' m delighted and honoured," he said. "The club has changed a lot since my day, but the support and passion of the fans has remained the same and I'm looking forward to meeting them as part of my new role."
Hailed as one of United’s finest ever players, Denis signed for United in 1962 – 50 years ago this season – for a then record fee of £115,000. He became an instant favourite with the Old Trafford crowd after he scored on his league debut in a 2-2 draw against West Bromwich Albion.
He then went on to become one of the most prolific goalscorers in United’s history and is widely regarded as one of the greatest players ever to wear the famous red shirt.
Denis won the 1963 FA Cup, championship medals in 1964/65 and 1966/67 and was named European Footballer of the Year in 1964. He played a key part in helping the Reds reach the 1968 European Cup final but missed the game due to a knee injury.
Manchester United chief executive David Gill said he's looking forward to working with Denis in