The 24-year-old, who has previously made senior appearances for Middlesex and Hampshire, has put pen to paper on a one-year deal having been on trial with the Green & Golds during their pre-season to date.
He joins Haseeb Hameed, Peter Trego and Mohammad Abbas – and new Assistant Coach Kevin Shine – in strengthening the Trent Bridge outfit in preparation for the 2020 campaign.
Standing tall at 6ft 3ins and identified as a promising fast-bowling talent from a young age, Barber has previously spent time working with Shine on the ECB’s pace programme.
“We’ve had the chance to take an extended look at Tom, and he’s fully earned his opportunity as part of our setup,” said Nottinghamshire Head Coach Peter Moores.
“His left-arm angle offers something different to our bowling attack and he bowls with genuine pace as well, which is an asset to any squad.
“He’s quickly gelled with the rest of the lads and has brought a work ethic that demonstrates his determination to make it in the professional game.
The Christchurch-based quick said: "I’m really looking forward to getting stuck in. Since I started training with the guys before Christmas, everyone has been really welcoming, and it’s going to be great to work with the likes of Paul Franks and Mooresy – as well as picking up with Shiney again.
“Trent Bridge is a really special place – it’s a Test ground, and plenty of great matches and performances have happened here, so I’m excited to hopefully get out there for Notts this summer.”