The former England U18 and U19 international has been a regular for the Northampton Wanderers side in the Aviva Premiership A League over the past three seasons, including playing against Gloucester United at Kingsholm back in October.
A product of Sedbergh School, he has also spent time on loan at Moseley in the Championship in 2012-13 and with Coventry in National One in 2011-12.
Director of Rugby Nigel Davies told the club website that linking up with Gloucester is a great opportunity for Hicks.
"Tom is a promising young prospect with the ideal build for a second row in the professional game.
"He's an ambitious young man, and he's opted to join us at Kingsholm because he feels we have a reputation for developing young talent and providing good playing opportunities for younger players where appropriate.
"He's already shown what he can do at A League level and this move is a chance for him to develop his game and push on.
"We see a bit of Alex Brown in him so we're looking forward to Tom arriving, getting down to some hard work with us and seeing where that takes him."