The Dons have strengthened their squad with seven signings ahead of the 2018 campaign.
Halifax prop forward Ryan Boyle and Hull KR half-back Liam Harris have both penned two-year contracts with the club.
Utility back Connor Bower has agreed a one-year deal after leaving Hull FC.
Doncaster have also agreed four season-long loan deals with their dual-registration partners Hull FC.
Jez Litten and Jordan Lane, who played for the Dons in Toronto last season, will spend the full season at the Keepmoat Stadium along with prop forward Ross Osborne and winger Jack Sanderson.
Boyle, 30, will add some much-needed experience to the Dons pack after the departures of Feka Paleaaesina and Jamie Thackray, and the front-rower is no stranger to challenging at the top after a spell in Super League with Castleford Tigers.
Boyle said: “The move made sense for me after leaving Halifax, I’m going to be working in and around the Doncaster area so it suits all parties really.
“I said to my agent that if we could get the deal done then this was the place I wanted to be, I had some really good conversations with Richard Horne and Carl Hall.”
Liam Harris will be no stranger to Dons fans having scored a sensational 90-metre try for York City Knights against them in last season’s Kingstone Press League One Super 8s.
The Hull-born 20-year-old came through the ranks at KCOM Craven Park and made his first team debut in the Championship against Sheffield Eagles last season.
The Dons have paid the Robins an undisclosed fee for Harris’s services, after fighting off competition from a number of clubs for his signature.
Bower can play all across the back line and is the fifth Hull FC man to join the Dons for the 2018 season.
Chief executive Carl Hall said: “All of the signings we have made will improve us in key positions for next season. We wanted quality over quantity and I believe we have got that.”
Richard Horne said: “The additions of Ryan Boyle and Liam Harris will significantly improve the strength we have in certain areas, we feel that we have brought in some real quality there.
“The lads coming from Hull FC will stay with us for the whole of 2018, which will enable them to develop and for us to get the best out of them.”
Aaron Jones-Bishop, Jordan Howden, Russ Spiers, Brad England, Jack Miller, Jason Muranka, Connor Scott, Zac Braham, Liam Welham and Kieran Cross have all renewed their deals with the Dons for the 2018 season.