The Catalpa rescue was the escape, in 1876, of six Irish Fenian prisoners from what was then the British penal colony of Western Australia.
From 1865 to 1867, British authorities rounded up supporters of the Irish Republican Brotherhood, an Irish independence movement, and transported sixty-two of them to the penal colony of Western Australia. They were convicted of crimes ranging from treason-felony to outright rebellion. Sixteen were soldiers who were court martialed for failing to report or stop the treason and mutinous acts of the others. Among them was John Boyle O'Reilly, later to become the editor of the Boston newspaper The Pilot. They were sent on the convict ship Hougoumont, arriving at Fremantle on 9 January 1868, at the Convict Establishment (now Fremantle Prison).
In 1869, O'Reilly escaped on the whaling ship Gazelle in Bunbury with assistance of the local Catholic priest, Father Patrick McCabe, and settled in Boston. Soon after his arrival, O'Reilly found work with The Pilot newspaper and eventually became editor. In 1871, another Fenian, John Devoy, was granted amnesty in England, among others, on condition that he settle outside Ireland, and he sailed to New York City. He also became a newspaperman, for the New York Herald. He joined the Clan na Gael, an organization that supported armed insurrection in Ireland.
In 1869, pardons had been issued to many of the imprisoned Fenians. Another round of pardons were issued in 1871, after which only a small group of "military" Fenians remained in Western Australia's penal system. In 1873, Devoy received a smuggled letter from imprisoned Fenian James Wilson, who was among those the British had not released. He asked them to aid the escape of the remaining Fenian prisoners. Devoy discussed the matter with O'Reilly and Thomas McCarthy Fennell, and Fennell suggested that a ship be purchased, laden with a legitimate cargo, and sailed to Western Australia, where it would not be expected to arouse suspicion. The Fenian prisoners would then be rescued by stealth rather than force of arms. Devoy approached the 1874 convention of the Clan na Gael and got the Clan to agree to fund a rescue of the men. He then approached whaling agent John T. Richardson, who told them to contact his son-in-law, whaling captain George Smith Anthony, who agreed to help.