James Alexander, 4th Earl of Caledon KP, DL (11 July 1846 – 27 April 1898) was a soldier and politician and the son of James Du Pre Alexander, 3rd Earl of Caledon and Lady Jane Grimston, styled Viscount Alexander until 1855.
He was born at his family's home in Carlton House Terrace, London and educated Harrow and Christ Church, Oxford. He succeeded to the title Earl of Caledon at the age of nine on the death of his father in 1855.
In 1861, during his minority, an extensive but remote property at Castlederg, County Tyrone, known as the Derg Estate, was purchased through the Landed Estates Court by his guardians from a kinsman of the Alexanders, Sir Robert Ferguson. The Caledon family took an active interest in the management of their estates. The 2nd and 3rd Earls made extensive improvements to the village of Caledon, erected the flour mill in the village, gave financial support to the poor of Caledon and to schools on the estate, and improved their property by draining, liming, etc. In addition, large sums of money were spent improving and extending the 'big house' at Caledon (variously known as Caledon House, Caledon Hill and Caledon Castle), and on laying out the richly ornamental demesne and gardens of over 600 acres (2.4 km2).
As an adult, Lord Caledon was elected to sit in the House of Lords as a Representative Peer for Ireland in 1877 and was Deputy Lieutenant of County Tyrone. He gained the rank of Captain in the service of the 1st Life Guards, became a Major serving with the 4th Battalion, Royal Inniskilling Fusiliers and fought in the Egyptian Campaign in 1882. He was also invested as a Knight of the Order of St. Patrick on 14 November 1896.
He married Lady Elizabeth Graham-Toler, daughter of Hector Graham-Toler, 3rd Earl of Norbury, on 9 October 1884 and had issue: