Oscar Thomas, Ashley Warne and Matty Ashton have joined Swinton on one-year contracts.
Thomas arrives at Heywood Road from Sheffield Eagles, where he scored three tries and kicked 22 goals in 18 games.
The 24-year-old has international honours with Scotland, earning 11 caps for the Bravehearts to date.
On signing Thomas, Swinton coach Stuart Littler said: “Oscar is an experienced Championship player who has previously been at London, Bradford and Sheffield.
“After meeting with Oscar, he fit our mould in being a player keen to develop and learn whilst also aiming to get back to producing his best football.
“I believe Oscar can be a consistent performer with our club and if he can get back to playing his best rugby league, he will be a very valuable attribute to our organisation. I am looking forward to working with Oscar, who will join our current internationals in returning to training this week.
“2019 is shaping up very nicely with the attitude and team ethos the boys are demonstrating in training. I feel adding Oscar will only supplement this as we strive to progress in 2019.”
Warne, 23, is a back-rower or loose forward who came through the academy at Salford Red Devils. He has been handed a deal after impressing on trial with the Lions.
Ashton is a utility-back, who caught the eye of Littler while playing for amateur side Rochdale Mayfield. The Lions fought off competition from other professional clubs to secure the services of Ashton.