The 27-year-old has scored 10 tries in 19 Super League appearances this term for the struggling Dragons.
The England international said: "I am delighted to have signed for the Rhinos and can't wait to get started when I join up with the boys at the end of the season.
"Leeds is a big club and a club that is always fighting for silverware."
Leeds Rhinos have signed Catalans Dragons half-back Richie Myler on a three-year deal, starting next season.