James Dalison Alexander was born on 5 March 1846, the son of James Alexander and Anna Maria Julia née Dalison. He was educated at Eton and gained the rank of Captain in the service of the West Kent Yeomanry Cavalry. On 27 January 1885 he married Lady Emily Harriet Catherine Boyle, daughter of the 9th Earl of Cork. The marriage produced four children.

James Dalison Alexander died on 21 October 1914.