Oliver Joseph St John Gogarty (17 August 1878 – 22 September 1957) was an Irish poet, author, otolaryngologist, athlete, politician, and well-known conversationalist, who served as the inspiration for Buck Mulligan in James Joyce's novel Ulysses.
Gogarty was born 17 August 1878 in Rutland Square, Dublin, the eldest child of Henry Gogarty, a well-to-do Dublin physician, and Margaret Gogarty (née Oliver), the daughter of a Galway mill owner. Three siblings (Henry, Mary, and Richard) were born later. Gogarty's father, himself the son of a medical doctor, had been educated at Trinity College and owned two fashionable homes in Dublin, which set the Gogartys apart from other Irish Catholic families at that time and allowed them access to the same social circles as the Protestant Ascendancy.
In 1887 Gogarty's father died of a burst appendix, and Gogarty was sent to Mungret College, a boarding school near Limerick. He was unhappy in his new school, and the following year he transferred to Stonyhurst College in Lancashire, England, which he liked little better, later referring to it as "a religious jail".