The nine-times English champions have agreed terms with Kieran Brookes, Graham Kitchener and Micky Young who are all currently with the England Saxons squad at the Churchill Cup.
Brookes, a prop, and scrum-half Young will move from Newcastle Falcons, while second-rower Kitchener was part of the Worcester Warriors squad which gained promotion to the Aviva Premiership in the 2010/11 season.
Tigers director of rugby Richard Cockerill said: “We’re delighted to be able to add such promising young talent to our squad. We hope they all enjoy a successful Churchill Cup this summer and we look forward to them joining us in time for the build-up to the new season.
“We’ve brought a number of young players through to our first-team squad in the last couple of seasons and we think these three have the potential to develop well within our environment.
“It is important for this club to retain a strong, young English core to the squad and we have an excellent record in that regard.”
Brookes, 20, has played almost 40 first-team games in two years with Newcastle, while 22-year-old Young has played 79 senior games since making his debut in 2007/08.
Kitchener, 21, was among the try-scorers in the England Saxons win over the USA last Saturday and made 32 appearances in Worcester’s Championship-winning season.
Nottingham Rugby, meanwhile, have announced that hooker Joe Duffey will be returning to the Green and Whites next season.
Duffey, who captained the Tigers Development XV to the Aviva Premiership A League title, said: "It will be great to be back amongst familiar surroundings. I’m really excited about the new season kicking off now.”