"Of the things which nourish the imagination, humour is one of the most needful, and it is dangerous to limit or destroy it. "

Edmund John Millington Synge was born on 16 April 1871, in Newtown Villas, Rathfarnham, County Dublin, Ireland. He was the youngest son in a family of eight children. His parents were part of the Protestant middle and upper class.  His family on his father's side were landed gentry from Glanmore Castle, County Wicklow and his maternal grandfather, Robert Traill, had been a Church of Ireland rector in Schull, County Cork and a member of the Schull Relief Committee during the Great Irish Famine (1845–1849).

His earliest poems are somewhat Wordsworthian in tone. His first literary composition was a nature diary he made in collaboration with Florence Ross when they were both children. Synge was educated privately at schools in Dublin and Bray, and later studied piano, flute, violin, music theory and counterpoint at the Royal Irish Academy of Music.

The family moved to the suburb of Kingstown (now Dún Laoghaire) in 1888, and Synge entered Trinity College, Dublin the following year, where he graduated with a BA in 1892. While at Trinity College, he studied Irish and Hebrew, as well as continuing his music studies and playing in the Academy Orchestra.

After graduating, Synge decided that he wanted to be a professional musician and went to Germany to study music. He stayed at Coblenz during 1893, and moved to Würzburg in January of the following year. Partly because he was shy about performing in public, and partly because of self-doubt on his ability, Synge decided to abandon music and pursue his literary interests. He returned to Ireland in June 1894, and moved to Paris the following January to study literature and languages at the Sorbonne. In 1896 he visited Italy to study the language for a time, before returning to Paris. Later that year he met W. B. Yeats, who encouraged Synge to live for a while in the Aran Islands and then return to Dublin and devote himself to creative work. Also that year, he joined with Yeats, Augusta - Lady Gregory, and George William Russell to form the Irish National Theatre Society, which later would establish the Abbey Theatre.

Synge suffered his first attack of Hodgkin's disease in 1897 and also had an enlarged gland removed from his neck. The following year, he spent the summer on the Aran Islands. He spent the next five summers on the islands, collecting stories and folklore and perfecting his Irish, while continuing to live in Paris for most of the rest of the year.

The play widely regarded as Synge's masterpiece, The Playboy of the Western World, was first performed in the Abbey Theatre on 26 January 1907. The comedy centers on the story of apparent parricide and attracted a widely hostile reaction from the Irish public. In 1907 Synge became engaged to the Abbey Theatre actress Maire O'Neill. He died in Dublin two years later on 24 March 1909.

The Complete Works of J. M. Synge is published by Wordsworth Editions.