Sir Thomas Tassell Grant KCB FRS (1795-15 October 1859) was a notable inventor in the 19th century. He was born in Portsea, Portsmouth, the son of a namesake and his wife Ann (née Tassell) of Soberton, Hampshire. In 1834 he invented a desalination plant which distilled fresh water at sea and was described by the Times in 1859 as "the greatest benefit ever conferred on the sailor, materially advancing the sanitary and moral condition of the navy". Installed on it produced 10,000 gallons a day during the Crimean War.