The winger joined City on a season-long deal at the end of August and scored once in 23 appearances.
Elmohamady's contribution helped Hull to second place in the Championship, and Martin O'Neill was impressed enough to cut short the agreement.
A statement from Hull read: "We would like to thank Elmo for his efforts and wish him all the best for the future."
Elmohamady will rejoin a Sunderland squad six points above the Premier League's relegation places and out of the FA Cup following Tuesday's defeat to Bolton.


 





