The 31 year old has managed to get himself a four year deal at the Stadium of Light, the fee Sunderland have paid is thought to be something around the £1million mark.
Sunderland had a joint bid of more than £12million for Brown, John O'Shea and Darron Gibson accepted last month and it was just a matter of time before they signed.
Republic of Ireland defender O'Shea is also believed to be taking a medical today at the Wearside outfit.
Manager Steve Bruce said: "We are delighted to welcome a player of Wes' ability, experience and character to the club.
"He has been a fantastic professional for Manchester United through the years and not only will he strengthen our defensive options, he will also bring with him a winning mentality and level of maturity which can only be positive for the players around him."