Green, 24, has received visa clearance and will join up with the Robins for pre-season training in November where he will link up with Michael Dobson, who he played alongside for the Australian schoolboys.
He said: “I’m really excited for coming over. I’ve been doing a bit of training so I’m ready for when pre-season starts and I’m champing at the bit to be honest.
“I’ve played a handful of games with Dobbo but that was a while back now. But I think it’s important that there’s a good understanding between players, particularly when you’re playing in the halves.
“We’ve got similar characteristics so that will stand us in good stead.”
Green has made more than 40 appearances in the NRL for the Bulldogs, Parramatta and Cronulla.
Head coach Justin Morgan said: “The signing of Blake is an important one in our plans for next season.
“Blake has a good all-round game and with the other creative players we have in the squad we’ll have a really good balance to the side.
“People like Scott Murrell put their hand up last season and did a really good job playing somewhere that we don’t consider to be his best position. Now we will have someone to call upon who is a natural stand-off which is an important component of any squad, and will help us push on again over the next couple of years.”