The son of former Wales international and current Director of Rugby at London Wasps, Dai Young, he was a regular in the Welsh age grade set up playing at U16 and U18 level, and represented the U20 side in the Junior World Championship in Italy in 2011.
He made his Cardiff Blues senior debut against Bath Rugby in 2010, in a 29-19 defeat in the LV= Cup.
Director of Rugby Nigel Davies, speaking to the local media, emphasised that Young certainly has talent and that the move to Gloucester could be a very good one for him.
"Thomas was very successful throughout the ages groups in Wales, a very combative seven, very good on the floor. He would have played against Matt Kvesic in the age grades and he's a similar type of player.
"The Blues have a number of good sevens, they're blessed in that position. He's played a number of times for the Blues, and has been at Pontypridd recently. But there's now an opportunity for him here, and we have a chance to take a good look at him for the rest of the season.
"He comes here full of enthusiasm and looking to make his mark. It's a win-win situation. He's got until the end of the season to show everyone here what he can do, and there may be chances for him here with the internationals just around the corner."