His manager Nima Safapour of Alchemist Management confirmed the signing to MMA Fighting on Tuesday morning.
Vieira is 13-7-1 in a career that dates back to 2001. Nine of his wins have come by submission, including three by anaconda choke.
Vieira has long been considered a key member of the famed Brazilian Top Team and taught the anaconda hold to Antonio Rodrigo Nogueira, who popularized it in a pair of 2004 PRIDE wins.
He fought most recently at a Strikeforce Challengers show last August, defeating Sterling Ford in a first-round technical submission. That victory stretched his win streak to three straight. Overall, he's won five of his last six bouts. During his career, he's also fought in PRIDE and M-1.
Safapour told MMA Fighting that Vieira does not yet have his octagon debut scheduled, but that the contract to move him from Strikeforce to UFC has been signed by all parties.