"Boro have completed the signing of Rudy Gestede from Aston Villa for an undisclosed fee," the club said on their website (www.mfc.co.uk).
The Benin international joined Villa from Blackburn in July 2015 and has scored 10 goals in 55 appearances.
Gestede found first-team opportunities limited at Villa and has started only three games since manager Steve Bruce took over at the Championship club in October.
Gestede becomes manager Aitor Karanka's first signing of the January transfer window and will hope to add some much-needed firepower to attack as Middlesbrough are the joint-lowest scorers in the league with 17 goals in 20 games.
Middlesbrough, who are 16th in the table with 19 points, four above the relegation zone, host Sheffield Wednesday in the third round of the FA Cup on Sunday.
(Reporting by Shravanth Vijayakumar in Bengaluru; Editing by Clare Fallon)
