In July 1754 she commenced "middling repairs", completed at a cost of £5,457.10.3d,[1] before she recommissioned under the command Charles Proby in October 1754.

On 18 December she sailed as part of Admiral Augustus Keppel's North American squadron during the French and Indian War.

[2] On 23 October 1756, under the command of Thomas Collingwood, she sailed for the Mediterranean Sea,[2] where she was engaged in escorting English merchant shipping.

[2] After fitting out at Sheerness Dockyard was completed in May 1761, at a cost of £2661.3.3d,[1] she served as part of the Downs Squadron.

[2] On 26 November 1761, Siren in company with Unicorn and the sloop Martin, chased and captured the 10-gun privateer cutter Ernestine of Dunkirk.