The Shaftesbury Homes and Arethusa is one of the United Kingdom's oldest children's charities. It has been active since 1843. Its aim, written in its current mission statement, is to support young people in care and need to find their voice, to be healthy, to learn, develop and achieve and to gain an independent and positive place in society.

HMS Arethusa was a 50-gun fourth-rate sailing frigate of the Royal Navy launched in 1849 from the Pembroke Dockyard. The fourth naval ship to bear the name, she served in the Crimean War and then in 1861 was converted to a steam screw frigate. Decommissioned in 1874, Arethusa became a school and training ship on the River Thames, preparing young boys for maritime careers, until she was broken up in 1934.