Commissioned lieutenant on 28 October 1750, Collingwood was posted captain of the frigate Syren 20 on 29 November 1756, serving in the Mediterranean. Having joined the new Crescent 32 in October 1758, he had her in the West Indies during the following year, being present at the recapture from the French of the frigate Berkeley 26 off Basseterre on 3 August 1759. He also captured the Hermione 26 on 16 August and the privateers Saint-Antoine on 15 August 1760, Saint-Michel on 22 August and Colibri on 2 March 1761. He later commanded the Crescent in Rear-Admiral George Brydges Rodney’s expedition against Martinique in the early part of 1762.
Moving to the Nottingham 60 in the spring of 1762, he joined the Jamaican station in April and with this vessel was present at the reduction of Havana during the summer. Having moved to the Temple 68 in September, he suffered the misfortune of losing his leaky ship on 18 December when she foundered off Cape Clear during the voyage home to England.
In the latter part of 1766 Collingwood commissioned the Tweed 36 for service in home waters, going out to Russia in 1768, and serving with the Duke of Cumberland’s squadron in 1769 before leaving her in the following year. At the end of 1771 he joined the Rainbow 44, undertaking a couple of voyages to West Africa in the winters of 1771-3, and reporting the discovery by his surgeon of a wine and bark remedy for fevers. In early 1774 it was reported that the Rainbow had been wrecked off Cape Blanco and that a ship was being sent to rescue the crew who were under regular attack by the natives, but this news soon proved to be without foundation. The Rainbow was paid off in September 1774.
He commissioned the new Monmouth 64 in January 1778, which vessel formed part of Vice-Admiral Hon John Byron’s squadron that went out to North America on 9 June 1778, the force becoming separated in a storm and the Monmouth springing her mainmast prior to her arrival in New York on 17 August. He immediately joined Vice-Admiral Lord Howe’s fleet, elements of which had a running battle with the French off Rhode Island in August. Removing to the Grafton 74 in 1778, he sailed with Byron for the Leeward Islands in December and lost 35 men killed and 63 wounded at the Battle of Grenada on 6 July 1779, these being the highest casualties in the fleet.
Towards the end of the year Collingwood raised his broad pennant aboard the Grafton with Captain Thomas Newnham as his captain in order to lead small squadron in the Leeward Islands. Commanding the centre division, he fought under Admiral Sir George Rodney at the Battle of Martinique on 17 April 1780, but unfortunately failed to grasp his senior’s complex signals and in trying to catch up with the van left his own division far behind.
Collingwood could not cope with his part in the failure, and having commanded a small squadron off Martinique with his broad pennant on the Terrible 74, Captain Archibald Dickson, and taken part in the skirmishes with the French fleet in May, he lost his senses. He was put aboard the frigate Brilliant 28, Captain John Ford, bound for Lisbon but sadly died in passage on 2 June.
He married Mary, the daughter of Captain Sir Richard Hughes, commissioner of the Portsmouth, who following his death married Lieutenant-Colonel Nathaniel Heywood. His address was given as Unthank, Northumberland.
Collingwood was esteemed by all, and in describing him as the ‘best and bravest’ officer, Admiral Rodney claimed to have done his utmost to assuage Collingwood’s self-blame for his failure in his last battle.