James Cunningham and Elliot Kear have signed contract extensions with London for 2019 and beyond.
Cunningham established himself as one of the best playmakers in the Championship last season, playing at both half-back and hooker.
The England Knights representative attracted a lot of interest from several Super League clubs for next season, but the Broncos have managed to retain him.
On his new deal, Cunningham said: “I am really happy to have secured another year at the club.
“Last season I felt I was playing really well and I hope I can carry that form into next year.
“I want to say thanks to Danny Ward and his team for having faith in me and helping me through the tough times and the good.
“I am now looking forward to playing with this great group of guys and continuing the journey onwards into the Super League.”
Meanwhile, Wales captain Kear has signed a new one-year deal with the club.
Kear will be moving into his fourth year at the club, having joined in 2015 from rugby union side London Welsh.
Cardiff-born Kear commented: “I am really happy to sign for another year here at London Broncos and to be going to Super League with the club.
“I am really excited about the next challenge in Super League and in keeping the London club where it belongs.”