The 30-year-old made 76 appearances for the Dons since becoming a member of from Scunthorpe United in 2019.
The Belgian midfielder will formally be part of Port Vale on July 1 when his Dons deal expires.
Funso Ojo has left Aberdeen to hitch English League One aspect Port Vale.
Port Vale’s director of soccer David Flitcroft stated: “As a membership, we’ve been in League Two for a very long time, and we’re about to make the step as much as a league that has bought some large hitters and groups with incredible managers and squads which have League One expertise.
“You take a look at that and also you need to need to make it possible for we add that have to strengthen what we’ve already bought and we additionally need to add to the intelligence ranges of the gamers.
“I feel from a training standpoint, we all know we’re going should give you totally different methods and we predict that Funso is the kind of participant that may conduct and orchestrate them on the pitch.
“We’ve bought somebody who has been on the stage and that’s key and it’s vital that we search for and might appeal to a participant with that type of profile.
“After we spoke to Funso, the joy and need for him to need to come and be part of this membership was evident, he couldn’t wait to come back over.
“We’re delighted to signal him and we will’t wait to see him on the pitch.”