Tuohy, an Ireland Under-21 international second row, was a member of the Gold Scholarship scheme at Hartpury last season and instrumental in Gloucester's Guinness A League success.
Last season he combined studying Sports Coaching and Conditioning with his rugby, but this season he will study part-time to fit in his Gloucester commitments and follows James Merriman and Jack Forster from Hartpury into the Kingsholm senior ranks.
"It is fantastic to get the opportunity to work alongside the senior squad and follow guys like James Merriman and Jack Forster off the Hartpury production line," Tuohy told www.gloucesterrugby.co.uk
"I was a member of the Hartpury first XV and Gloucester's A side and the opportunity just came from there - it will be awesome to learn from such experienced players and I am thoroughly looking forward to the challenge."
Tuohy (21) is comfortable at either four or five and played for Weston-super-Mare in National Three South before starting his degree at Hartpury.
"I just want to try and develop myself this season into a better player and I believe I am in the best environment to do that."
He will be joined in the squad by 18-year-old Dean Miller, who was part of the victorious St Peter's side who won the prestigious Daily Mail Cup at Twickenham last season.
Although he played at number eight during the cup run, his preferred position is blindside and he comes from a celebrated rugby playing family.
His father Colin enjoyed a wonderful career at city club Matson and also with Gloucestershire and Miller said: "Last season Will Matthews got injured and that was very unfortunate for him but I was the next person in line and tried to take my chance in the Guinness A League.
"I left school and joined Gloucester straight away - it's a fantastic opportunity - and I just intend to work as hard as I can and try and take any opportunities that come my way.
"After that, I will just see where it takes me. It is just very exciting to be a local lad and come through at Gloucester."