George Coppinger Ashlin (28 May 1837 – 10 December 1921) was an Irish architect, particularly noted for his work on churches and cathedrals, and who became President of the Royal Institute of the Architects of Ireland.

He was educated at St Mary's College, Oscott; and subsequently was a pupil of Edward Welby Pugin, whose partner he became in Ireland from 1860 to 1868.

[2][3] He was the architect of Queenstown Cathedral in Cobh, County Cork, and of fifty other churches dotted about Ireland.

He also built Portrane Asylum at a cost of £300,000.

[2] He was a Member of the Royal Hibernian Academy and Fellow of the Royal Institute of British Architects.