HMS Arethusa was a Leander-class frigate of the Royal Navy. She was, like the rest of the Leanders, named after a figure of mythology. Arethusa was built by J.S. White & Company Shipbuilders of Cowes, launched on 5 November 1963 and commissioned on 24 November 1965.
In 1967, Arethusa deployed to the Mediterranean. At the end of 1967 she was docked down for a repair period finishing in the spring of 1968. In the same year she took part in Portsmouth 'Navy Days'. After re dedication the ship worked up at Portland, later deploying to the Mediterranean. In 1969 Arethusa together with Juno, Hampshire and RFA Lyness visited Barbados, transited the Panama Canal and proceeded to Callao in Peru, Valparaiso, the Falkland Islands and Montevideo returning to the UK for Easter.
Later in 1969 Arethusa was deployed as West Indies guard ship. Visits included Punta Del Garda, Bermuda, Washington DC, Norfolk Virginia, Key West, Anguilla, Antigua, St Lucia, Curaçao, St Kitts, Tortola, St Vincent, Carriacou, Nassau, Freeport Grand Bahama, transiting the Panama Canal again to San Diego and San Francisco; returning via the Panama Canal to Trinidad. She continued to Cartagena, Dominica, St Martin, Bequia, Georgetown, Belize, Fort Lauderdale arriving in Portsmouth in April 1970. Arethusa was guard ship for the hand-over of independence to British Guiana.
In 1970, after visits to Lorient and Esbjerg, Arethusa deployed to the Far East via South Africa and her first Beira Patrol, While in the Far East she visited Penang, Singapore, Hong Kong, Nagoya, and the Philippines. On returning to Singapore she helped escort HM the Queen and HRH the Duke of Edinburgh on their South East Asian tour. In 1972, Arethusa undertook a further Beira Patrol which was designed to prevent oil reaching the landlocked country of Rhodesia via the then-Portuguese colony of Mozambique. The following year, Arethusa undertook a fishery protection patrol during the Second Cod War, and during that patrol was rammed by the Icelandic gunboat Óðinn.
In 1973 Arethusa began her modernisation which included the removal of her one twin 4.5-in gun, with the Ikara anti-submarine warfare missile system taking its place. The modernisation was completed in April 1977. In that same year, Arethusa, like many Leanders, took part in the Royal Navy's Fleet Review in celebration of HM the Queen's Silver Jubilee. Arethusa was positioned between Cleopatra and Arrow and was part of the 3rd Frigate Squadron. In 1979, Arethusa deployed to the Far East and Pacific.
In 1980 Arethusa underwent a refit that was completed the following year. She then joined Standing Naval Force Atlantic, a NATO multi-national squadron. In 1985, Arethusa was fitted with towed array sonar.
On 4 April 1989, at Portsmouth, Arethusa decommissioned. She was eventually sunk as a target in 1991.Colledge, J. J.; Warlow, Ben (2006) . Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8. OCLC 67375475.
Marriott, Leo, 1983. Royal Navy Frigates 1945-1983, Ian Allen Ltd. ISBN 07110 1322 5