HMS Raisonnable was a 64-gun third-rate ship of the line of the Royal Navy, named after the ship of the same name captured from the French in 1758. She was built at Chatham Dockyard, launched on 10 December 1768 and commissioned on 17 November 1770 under the command of Captain Maurice Suckling, Horatio Nelson's uncle. Raisonnable was built to the same lines as HMS Ardent, and was one of the seven ships forming the Ardent class of 1761. Raisonnable was the first ship in which Nelson served.

Captain Maurice Suckling was a British Royal Navy officer of the eighteenth century, most notable for starting the naval career of his nephew Horatio Nelson and for serving as Comptroller of the Navy from 1775 until his death. Suckling joined the Royal Navy in 1739 and saw service in the English Channel and Mediterranean Sea during the War of the Austrian Succession. With the support of relatives including Prime Minister Sir Robert Walpole, Suckling was promoted quickly and received his first command in 1754. At the start of the Seven Years' War in 1756 he was promoted to captain and given a command on the Jamaica Station. There he played a major part in the Battle of Cap-Français in 1757 and fought an inconclusive skirmish against the French ship Palmier in 1758 before returning to Britain in 1760.