Thornton was a cutter launched in 1793 at Southampton that the Sierra Leone Company purchased to assist in their activities.

Lloyd's List for 4 May 1792 reported that Amy, Patterson, Lapwing, Robinson, Harpy, Wilson, and 15 ships from Halifax, Nova Scotia had arrived at Sierra Leone.

Her mission was to visit the forts on the way to purchase African commodities and bring them back to Freetown.

[3] In September 1794 a French naval squadron comprising the razee Experiment under the command of lieutenant de vaisseau Arnaud, Vigilance, Félicité, Pervie, and Mutine was cruising the West African coast, destroying British factories and shipping.

[6] On 6 October 1794, after setting fire to the company's remaining buildings, the French gave "the Company's schooner" Thornton to an American slave trader named Mariner as a reward for his services to them.