Through the Irish pupils in the school he became known to Henry Ussher, afterwards professor of astronomy at Trinity College Dublin, who procured him admission as a sizar to that university.

His proficiency in the latter subject gave him some hope of succeeding his friend and patron, Ussher; but the appointment of John Brinkley in 1792 led to his devoting himself to the career of a family tutor, an occupation he followed for many years.

[2] In 1811 Bishop Cleaver gave him the rectory of Llanarmon Dyffryn Ceiriog, and in 1814 he was presented by Lord Crewe to the vicarage of Madeley, Shropshire.

His monument in the church styles him in legibus, moribus, institutis, annalibus, poesi, musica gentis Cambro-Britannicæ instructissimus ('most instructed in the laws, manners, institutions, annals, poetry, and music of the Welsh-British race').

According to the Dictionary of National Biography, Roberts was a scholar of wide reading but inferior judgment and the Cambrian Popular Antiquities, dealing with Welsh rustic customs and superstitions, is his most valuable contribution to letters.