Italian international Esposito plays in the pack and has previously played rugby union at centre.
Before joining Dewsbury at the end of last year, the forward played for York City Knights, joining them in June of 2012.
Eagles Head Coach, Mark Aston said, “It’s great to announce to signing of Dario.
“He is full of commitment and enthusiasm, exactly the type of qualities I look for in a player. He has a great work ethic too and with competition for places right across the squad this year, he’ll need that to fight his way into the starting 17.
“He’s only played Rugby League for four years but he’s great on the feet and can hit hard and run hard and I’m sure he’ll fit in great here at the Eagles.”