Seumas or Seamus O’Sullivan (born James Sullivan Starkey; 17 July 1879 – 24 March 1958) was an Irish poet and editor of The Dublin Magazine. His father, William Starkey (1836-1918), a physician, was also a poet and a friend of George Sigerson.

He was born in Dublin and spent his adult life in the suburb of Rathgar.

In 1926, he married the artist Estella Solomons, sister of Bethel Solomons. Her parents were opposed to the marriage as Seumas was not Jewish