Thomas received his first major commission in 1965, creating a bust of then Secretary of State for Wales, Jim Griffiths.

[1] Thomas received several commissions that are now public works of art, with permanent residency in major city centres.

Thomas's Mother and Child sculpture, commissioned for the building of a new shopping precinct at Coalville, Leicestershire won him the Sir Otto Beit prize for 1963.

[2] Robert Thomas sculptures are prominently displayed in Cardiff Queen Street, in the heart of the Welsh capital's shopping district.

He has four on display there (i) Nye Bevan (at the head of Queen Street, opposite the Castle); (ii) Mother and Son; (iii) The Family; and (iv) The Miner.