John Boyle O'Reilly (28 June 1844 – 10 August 1890) was an Irish poet, journalist, author and activist. As a youth in Ireland, he was a member of the Irish Republican Brotherhood, or Fenians, for which he was transported to Western Australia. After escaping to the United States, he became a prominent spokesperson for the Irish community and culture through his editorship of the Boston newspaper The Pilot, his prolific writing and his lecture tours.

Born in Dowth, O'Reilly moved to his aunt's residence in England as a teenager and became involved in journalism before enlisting in the British Army shortly thereafter. In 1863, he left the army after becoming discontented with British rule in Ireland. In 1864, after he had returned to Ireland, O'Reilly joined the Irish Republican Brotherhood under an assumed name and was part of the group for two years until he and many others were arrested by the British authorities in early 1866. After a trial the same year he was sentenced to death which was subsequently commuted to twenty years of penal servitude. In 1867, O'Reilly was transported to Western Australia and moved to the town of Bunbury where he escaped two years later. He was assisted in escaping by a Fr. Patrick McCabe from Arnaghan, Gowna, Co. Cavan.

After the escape O'Reilly moved to Boston and embarked on a successful writing and journalism career that produced works such as Moondyne (1879) and Songs from the Southern Seas (1873), and poems such as The Cry of the Dreamer and The White Rose and In Bohemia. He married Mary Murphy in 1872 and had four daughters. In the last 4 years of his life he suffered various health issues before dying of an overdose in his summer home in Hull, Massachusetts in 1890. His memorial service held at Tremont Temple was a major public event.

O'Reilly's literature and work with civil rights have been celebrated throughout the years.