Blind is expected to sign a contract with Ajax that will run until 2022.
The 28-year-old versatile defender and midfielder joined United in 2014 after impressing with Netherlands at the World Cup under Louis van Gaal, who was behind his €18.3m move to Old Trafford.
His versatility made him a dependable asset for Van Gaal and Jose Mourinho afterwards, playing in a variety of positions including centre-back, left-back and defensive midfield.
But, since Mourinho's arrival, Blind has seen his playing time substantially decrease with the Portuguese coach seeming unsure as to his best position.
After making 35 league appearances, all starts, in Van Gaal's final year at the helm in 2015-16, he would play just 23 Premier League games under Mourinho in 2016-17.
That was reduced to just seven appearances for United in the Premier League last season as a result of injuries and being out of favour, with four of those appearances coming from the start.
United kept clean sheets in all of his starts, but with just one year left to run on his contract, a sale had been mooted for several months.
A former Ajax youth academy prospect, Blind made his debut with the Eredivisie side in 2008 and went on to play 143 times with the club. He was part of four title winning teams with Ajax.
Ajax chief executive Edwin van der Sar said told Omnisport on Sunday that he was excited about the imminent arrival of the fan favourite.
"I think Daley is a fantastic player," he said.
"He's multi-functional, can be a left-back, centre-half and a defensive midfielder. For Netherlands and for Manchester United, he played many good games... it would be a great addition for Ajax to have a player with the quality of Daley to fit in the team."