From 1951 to 1959 he taught in Portsmouth, Hampshire. During this period he wrote The Enemy in the Heart (1957).
In 1959 Jones accepted an appointment as a lecturer (senior lecturer from 1962) in English at University of Newcastle in Newcastle, New South Wales, and so emigrated to Australia. In Australia were published his Songs of a Mad Prince (1960) and The Beast at the Door (1963).
He drowned accidentally at Newcastle in January 1965. He was survived by his wife, Madeline Scott, and three daughters. His book, The Colour of Cockcrowing was published posthumously in 1966. The Collected Poems of T. Harri Jones appeared in 1977.
Jones wrote poetry in English rather than Welsh. Although his father spoke Welsh and English, his mother spoke only English, and that was the language which Harri and his siblings adopted.