Centre Tyson has signed a three-year contract, whilst prop Neal has committed to a two-year deal.
Both players were part of the Roughyeds’ title-winning League 1 squad last season, and will now go full-time with the Eagles.
“I am thrilled to bring two young, hungry and talented individuals into the Sheffield Eagles fold,” director of rugby Mark Aston told www.sheffieldeagles.com.
“I have been an admirer of both for sometime, and they are two players with bags of ability who will really thrive in the full-time environment.
“They were standout performers in what was a very talented and successful Oldham outfit last season, and they know what it takes to ensure success.
“They are great lads who have the right mental attitude, and I know that they are really excited about the challenge ahead.
“I’d like to thank Chris Hamilton and Scott Naylor at Oldham for their assistance and professionalism in helping us bring George and Adam to the club.
“They fully understand that the chance to join a club that will be operating full time is a great opportunity for both these players, and Oldham have been very supportive during this process.”