Herbert John Cairns, 3rd Earl Cairns (17 July 1863 – 14 January 1905), was a British peer.
Cairns was born in London, the third son of Hugh Cairns, 1st Earl Cairns, a British statesman who served as Lord Chancellor of the United Kingdom during the first two ministries of Benjamin Disraeli, and Mary Harriet MacNeile. He was educated at Wellington College, Berkshire. He was a partner in the Elswick Ordnance Company. He succeeded in the earldom on the death of his older brother Arthur Cairns, 2nd Earl Cairns on 14 January 1890.
Cairns died on 14 January 1905 aged 41 at Union Golf Club, Cannes, France; he was unmarried. Cairns was buried on 23 January 1905 at Bournemouth in Hampshire. He was succeeded in the earldom by his younger brother Wilfred Dallas Cairns, 4th Earl Cairns
- Cokayne, and others, The Complete Peerage, volume II, page 471
- G.E. Cokayne; with Vicary Gibbs, H.A. Doubleday, Geoffrey H. White, Duncan Warrand and Lord Howard de Walden, editors, The Complete Peerage of England, Scotland, Ireland, Great Britain and the United Kingdom, Extant, Extinct or Dormant, new ed., 13 volumes in 14 (1910-1959; reprint in 6 volumes, Gloucester, U.K.: Alan Sutton Publishing, 2000), volume II, page 472