The 23-year-old former Right to Dream Academy graduate joins the Black Cats from Brighton and Hove Albion.
Adingra signed for the Seagulls from FC Nordsjaelland in 2022 but spent the 2022-23 season on loan at Belgian club Royale Union Saint-Gilloise.
Last term though, Adingra made 29 Premier League appearances scoring twice and adding two assists.
He has signed a five-year deal at the Stadium of Light and becomes Sunderland's sixth signing as they prepare for their first season back in the Premier League since the 2016/17 season.
A delighted Adingra told the club's website: "It's a pleasure to be here, and I cannot wait to get started.
"The club and the project are really exciting. I spoke with everyone and their interest in me made the decision easy - I wanted to be part of Sunderland's future.
"Playing in the Premier League has been a dream of mine since I was a kid, so to continue doing that is incredible. It's a big challenge ahead â- we'll be facing top players and strong opponents - but I'm ready for it."
Adingra joins fellow new signings Enzo le Fee, Habib Diarra, Noah Sadiki, Reinildo Mandava and Chemsdine Talbi at the club.