The slave ship Mary arrived with enslaved Africans in Guyana. About 189 people had been taken aboard and approximately 173 arrived.

Vessel: Mary; flag: Great Britain; rig: Brig; estimated standardized tonnage: 132. People recorded in connection with the voyage: Investor: McDowal, Samuel; Investor: Twemlow, Thomas; Captain: Mitchell, John; Investor: Mitchell, John. The voyage began at Liverpool on 26 December 1803. Principal recorded place where captives were acquired: Bight of Biafra and Gulf of Guinea Islands, port unspecified. Principal recorded disembarkation place: Demerara. Recorded outcome: Voyage completed as intended.