Built in 1794, Chatham.
Broken up in 1815.
- 1794 Capt. CAYLEY.
- 1795 Capt. Thomas WILLIAMS, 07/1795.
On 29 August 1795, in company with DIANA and SEAHORSE, Capt. WILLIAMS captured an East Indiaman and a whaler which had been escorted from the Cape of Good Hope by the Dutch brig of war, COMET (18).
The following day the COMET was captured by UNICORN.
- At daybreak on 8 June 1796 UNICORN and the SANTA MARGARITTA frigate were cruising to the westward of the Scillies when two large French frigates and a corvette were sighted.
They chased them all day until the rearmost enemy ship, TAMISE (42), finding that it was impossible to escape, in spite well directed fire from her stern-chasers, turned to rake SANTA MARGARITTA, but her commander, Captain Thomas MARTIN, was more cunning, and laid his ship alongside the enemy, and in twenty minutes forced her to strike.
- The other frigate, seeing the fate of her companion, attempted to gain the weather gage of UNICORN, but the good seamanship of Capt. WILLIAMS foiled the attempt, and a running fight ensued which lasted for ten hours.
The impasse was ended when Capt. WILLIAMS closed his opponent and there was a concentrated exchange of fire for about 35 minutes.
When the smoke cleared he saw that the Frenchman had tried to drop back and pass across UNICORN's stern.
UNICORN's sails were immediately put aback and the ship gained stern-way to resume her former position alongside the enemy.
A few minutes later, with only her mizzen-mast standing, the French frigate surrendered. She was the TRIBUNE, pierced for 48 guns, but only 44 mounted, and commanded by Commodore Moulson.
37 of the complement of 229 men were killed and 15, including the Commodore, wounded.
The UNICORN had only about 240 of her normal complement of 251 on board, a lieutenant and her best seamen being away in a prize. She had no casualties.
- As a reward for his conduct he was knighted shortly after he returned to port.
- On 7 January 1797 DORIS.36, UNICORN, and DRUID (32) captured the French frigate VILLE DE L'ORIENT, armed en flute with 400 hussars on board.
- 1797 Capt. James YOUNG, 03/1797.
- 1799 Capt. WILKINSON, 04/1799.
On the 18 March 1799 she arrived in Plymouth from a cruise.
URANIA (44) FIORENZO (40), and UNICORN sailed from Plymouth on 4 June with closed orders to be opened at a certain latitude.
Ten days later UNICORN sent in a prize, the French brig ST. ANTOINE.
On 21 July, in consequence of orders from the Admiralty, MELPOMENE, PROSELYTE, UNICORN, POMONE and NEREIDE, sailed from Plymouth for Cork and Waterford to take in troops for the Downs.
On 28 September she was back in Plymouth after a cruise.
- 1800 On 18 June UNICORN brought into Plymouth from off the Penmarks ten sail of brigs and chasse-maree, deeply laden with provisions and brandy for the French fleet at Brest.
Eleven of them had been cut-out from under the batteries by the boats of RENOWN, Rear Ad. Sir John WARREN, DEFENCE, FISGARD and UNICORN.
One foundered but the crew were saved. She sailed again on the 27th. to rejoin the fleet.
On 12 July she came in with dispatches for Rear Ad. WITSHEAD and returned to the fleet the same evening.
On 21 September she brought in to Plymouth 160 Spanish prisoners from Corunna
- 1801 Capt. WEMYSS, Channel.
In the summer UNICORN and the ATALANTE sloop were employed watching the coast off Quiberon.
Capt. WEMYSS successfully prevented convoys from moving out of the Morbihan but although the boats were sent away on several occasions he only managed to capture one chasse-maree, which was not worth sending in, and destroying one.
One seaman was killed and another wounded.
On 14 August he wrote to Ad. CORNWALLIS to say that he had barely a month's supply of provisions.
- 1803 repairing at Chatham.
- 1805 Capt. Lucius HARDYMAN, Plymouth, for the Jamaica station where he captured the French schooner TUP a-BORD, with four 6-pounders and 46 men, in the spring.
The Spanish ship NOTRE DAME DEL CARMEN taking cocoa from Havana to Cadiz was taken on 15 October.
- On 7 October 1806 to Buenos Aires where Capt. HARDYMAN directed the covering vessels when the troops landed to attack Monte Video which was captured on 3 February 1807.
UNICORN's casualties were John JAMES, ordinary seaman, and Henry SMITH, midshipman, both severely wounded.
- 1808 Plymouth.
- UNICORN was with Lord GAMBIER in the Basque Roads in March 1809.
On 11 April AIGLE, UNICORN, PALLAS and IMPERIEUSE anchored near the Boyart shoal to receive the crews of the fireships on their return and support the boats accompanying the fireships.
- 1809 Capt. Alex.
Robert KERR, 08/1809, cruising.
While under his command UNICORN captured the French privateer GASCON of 16 guns and 113 men from Bayonne on 3 February 1810 and, on 12 April, recaptured the former HM
ship LAUREL (22). She had been taken by CANNONIERE off Mauritius on 12 September 1808 and renamed ESPERANCE. She was armed en flute with a valuable cargo of East India produce.
Back in the Royal Navy she was renamed LAURESTINUS.
- In April 1811 Capt. KERR was appointed to ACASTA.
- In the autumn, Capt. G. B. SALT, Corunna.
On 30 March 1813 UNICORN and STAG captured the French privateer ship MIQUELONNAISE south of the Scillies. She mounted two long 12-pounders, eight long 6-pounders and eight 12-pound carronades and had a complement of 130 men.
In the four days she had been out from Quimper she had taken and sunk the ALEXANDER, a small brig bound for Lisbon from London with iron and tin.
In April STAG and UNICORN captured the American letter of marque schooner HEBE, John Picarare, master, bound to Bordeaux or Nantes. She was found to be his Britannic Majesty's schooner LAURA, captured by the privateer DILIGENT off North America on 8 September 1812.
- In June Capt. SALT was attacked with apoplexy.
He was dressing himself on his arrival from Plymouth, to wait upon Sir Richard BICKERTON, when the palsy came on and for some time he was in a state of danger.
- 1814 Capt. S. G. PECHELL, off Flushing.
- 1815 Out of