William Ellis Gloag, Lord Kincairney (7 February 1828 – 8 October 1909) was a Scottish judge.

Gloag was born in Perth on 7 February 1828 to Jessie (née Burn), daughter of John Burn, Writer to the Signet, and William Gloag, a banker in Perth. Paton James Gloag the theologian writer and Moderator of the General Assembly of the Church of Scotland in 1889, was his eldest brother, and his eldest sister was Jessie Burn Gloag, who founded a ragged school in Perth.^[1]

Gloat was educated at Perth grammar school and the University of Edinburgh. He passed the Scottish bar on 25 December 1853, where he enjoyed a fair practice. A Conservative in politics, he was not offered promotion until 1874, when he was appointed advocate depute on the formation of Disraeli's second ministry.^[1]

In 1877, Gloag became Sheriff of Stirling and Dumbarton, and in 1885 Sheriff of Perthshire. In 1889, he was raised to the bench, when he took the title of Lord Kincairney.

In later life he owned a large Georgian townhouse at 6 Heriot Row, Edinburgh which had previously been the home of the author Henry Mackenzie.^[2]

He died at Kincairney on 8 October 1909, and was buried at Caputh.^[1] He is also memorialised on his brother Paton's grave in Dunning.^[3]

• Introduction to the Law of Scotland, Green, 1995

In 1864, Gloag married Helen, daughter of James Burn, Writer to the Signet. Together they had three daughters and a son, William Murray Gloag.^[1]