HMS Assistance was a 40-gun fourth-rate frigate of the Royal Navy, originally built for the navy of the Commonwealth of England at Deptford, and launched in 1650. By 1677 her armament had been increased to 48 guns. Her third rebuild was carried out at Limehouse, from where she was relaunched on 16 February 1713 as a 50-gun fourth rate to the 1706 Establishment. On 21 March 1720 she was ordered to be taken to pieces at Woolwich for what was to be her final rebuild. She relaunched as a 50-gun fourth rate to the 1719 Establishment on 25 November 1725. Assistance was sunk as a breakwater in 1745.