Archibald Seton Montgomerie, 16th Earl of Eglinton and 4th Earl of Winton DL (23 June 1880 – 22 April 1945), styled Lord Montgomerie from 1892 to 1919, was an English aristocrat who abandoned Eglinton Castle, the family seat or 'caput', in 1925.

[3] During World War I, he served with the Life Guards, where he was mentioned in despatches.

[2] Upon the death of his father on 10 August 1919, he succeeded as the 16th Earl of Eglinton in the Peerage of Scotland, the 5th Baron Ardrossan, the 17th Lord Montgomerie, and the 4th Earl of Winton in the Peerage of the United Kingdom, which enabled him to sit in the House of Lords.

He served as a Deputy Lieutenant of Ayrshire[4] On 1 June 1908, he married Lady Beatrice Susan Dalrymple, a daughter of John Dalrymple, 11th Earl of Stair and the former Susan Harriet Grant-Suttie (a daughter of Sir James Grant-Suttie, 6th Baronet and Lady Susan Harriet Innes-Ker).

[2] Through his daughter Lady Barbara, he was a great-grandfather of Georgina Fitzalan-Howard, Duchess of Norfolk.