Admiral Richard Darton Thomas (3 June 1777 – 21 August 1857) was an officer of the British Royal Navy who served during the French Revolutionary and Napoleonic Wars, and went on to become Commander-in-Chief, Pacific Station in the 1840s.

On 1 January 1793 France declared war on Great Britain, and for the next two years Thomas served aboard Nautilus in the West Indies under the Captains Lord Henry Paulet, James Carpenter, Henry William Bayntun, and William Gordon Rutherford, while taking part in operations against the French islands of Tobago, Saint Lucia, and Martinique, where he commanded a boat in the attack on Fort Royal, landing and escalading the walls simultaneously with Captain Robert Faulknor of the sloop Zebra.

[1] On 15 January 1797 Thomas was commissioned as a lieutenant aboard the 74-gun Excellent, commanded by Captain Cuthbert Collingwood, and took part in the Battle of Cape St Vincent on 14 February.

From December 1799 until the signing of the Treaty of Amiens in March 1802 brought a temporary peace, Thomas served as flag lieutenant to Collingwood in the Triumph and Barfleur on the Channel Station.

From June 1802 he served aboard the Cambrian and Leander, the flagships of Sir Andrew Mitchell, Commander-in-Chief on the North American Station, based at Halifax, Nova Scotia.

After taking the French vessel as prize, Lady Hobart continued on her voyage, but during the night of 28 July struck a large iceberg, and foundered.

Despite encountering heavy rain, gales and thick fog, they made a landfall at Lower Island Cove on 4 June, all suffering from various degrees of malnutrition and frostbite.

On 22 October 1805, following the victory at Trafalgar, he was posted into Bellerophon briefly, before serving aboard the Queen, Ocean and Ville de Paris as flag captain to Lord Collingwood, engaged primarily on the blockade of Toulon.