The Tanzanian striker put pen to paper on a four-and-half year deal subject to a work permit and international clearance being granted.
Samatta, 27, scored ten goals for Genk in all competitions this season including a goal at Anfield against Liverpool in the Champions League.
Dean Smith said: “I’m really pleased we have managed to bring Mbwana to the club.
“He has scored goals throughout his career and I’m looking forward to working with him.”
The striker, represented Tanzania at the 2019 Africa Cup of Nationsb. He began his professional career with Simba SC in his homeland, and is the reigning holder of the Ebony Shoe the prize awarded to the best African player in Belgium.