Lieutenant Thomas Algernon Smith-Dorrien-Smith JP DL (7 February 1846 – 6 August 1918) was Lord Proprietor of the Isles of Scilly from 1872 until his death in 1918.

He succeeded his uncle, Augustus Smith, as Proprietor of the Isles of Scilly in 1872, and continued the development of the Tresco Abbey Gardens.

William I, German Emperor, awarded him the Order of the Red Eagle and his wife a gold bracelet for their work with survivors.

[7] A friend, Edward Rodd, in his annual report to the Royal Institution of Cornwall records the number of birds shot by Lt Smith-Dorrien-Smith during the Isles of Scilly shooting season.

Rodd also received an immature purple heron (Ardea purpurea) and a wood sandpiper (Tringa glareola) for his collection.