The 31-year-old, who spent two seasons at Cougar Park, is the Parksiders’ third signing of the off-season.
A former Doncaster and York City Knights player, Emmett was ever-present for Keighley this year scoring two tries in 26 appearances.
He said: “I’m really excited about next year at Hunslet.
“Our aim is to get the club promoted and that’s a challenge I am relishing.”
He added: “It was easy decision to sign for Hunslet after speaking to Gary [Thornton, Hunslet’s coach].
“It’s clear where he wants to take the club and I can’t wait to get started.
“These are exciting times for the club.
“Gary and Darren [Williams’ director of rugby] have worked hard to keep the guys who are staying and attract some real quality to the squad.”
Thornton has coached Emmett in the past and enthused: “Mike has lots of experience in League One.
“He is a tough, robust forward and has been in some very good teams during that time.
“I’ve worked with Mike before and he’s the sort of player you want in your camp and not in the opposition’s.
“He’s tough and has good skills and I’m hoping he can add those qualities to our group.
“He is another great addition to the squad.”