He was the eldest son of John Walsh, a merchant, of Ballymountain House, co. Waterford.

Before leaving Waterford he founded a literary society there, an account of which by him appeared anonymously in the ‘British Magazine,’ 1830 (ii.

While a student in Edinburgh he published several sketches of some merit, one of which (a view of the side of Calton Hill on which a facial resemblance to Nelson could at that time be traced) appeared in ‘Ackerman's Repository.’ Walsh began his professional career as medical officer on a West Indian packet.

He was afterwards physician to the forces in Ireland, being present at the battles in Wexford in 1798, and at the surrender of Humbert at Ballinamuck.

He collected a vast amount of information for a statistical history of Canada, but never published the work.

He published a ‘Narrative of the Expedition to Holland’ (London, 1800, 4to), and a collection of poems entitled ‘Bagatelles’ (1793); and wrote for the ‘Edinburgh Medical Journal,’ the ‘Amulet,’ &c. A portrait of him was painted by John Comerford, and an engraving of it appeared in the ‘Dublin University Magazine’ (1834, vol.