Lionel Arthur Henry Seymour Dawson-Damer, 6th Earl of Portarlington (26 August 1883 – 4 July 1959) was an Anglo-Irish peer and soldier.

William Frederick Martin), Lt. George Seymour Dawson-Damer (who was killed in action during World War I), Lady Moyra Dawson-Damer (wife of James Brinsley Peter FitzGerald, a grandson of Sir Peter FitzGerald, 19th Knight of Kerry).

[4] Upon the death of his father on 31 August 1900 at the Royal Palace Hotel at Ostend,[7] he succeeded as the 6th Earl of Portarlington, in the Peerage of Ireland, as well as the 7th Lord Dawson and the 7th Viscount Carlow.

He served as one of the King's train-bearers at the Coronation of Edward VII and Alexandra at Westminster Abbey, London, on 9 August 1902.

[8][9] Lord Portarlington was commissioned a lieutenant in the 4th (Militia) Battalion, the Prince of Wales's Leinster Regiment (Royal Canadians) on 21 December 1901.

1938), who served as a Page of Honour to Queen Elizabeth II before succeeding his grandfather as the 7th Earl of Portarlington, and Hon.

Lionel John Charles Seymour Dawson-Damer (1940–2000), who died in a motor-racing accident at Goodwood House.