John Colahan

John Colahan (born 1836) was Surgeon Major General in the British Army.

His father was the son of Professor Nicholas Colahan (1806–1890) and Sarah Whistler (1814–49). Their children were John (born 1836), Frances (born 1843), William H. W., and Nicholas, whose eldest son was the songwriter Arthur Colahan.

Colohan graduated M.D. at Queen's University, Galway in 1857, and served as an army surgeon in India, Gibraltar and Malta.

He married Eliza McDowel Orr (1859–1899), a concert pianist, in 1885. Their children were Merita (1886), Beatrice (1889), Frederick (1892), Jack (1894), the artist Colin Colahan (1897) and Basil (1899) He served as Principal Medical Officer in Ireland. The family from Dublin to Cape Town in 1889, then to Victoria, Australia in 1896.