بويل
Cryan was the son of Robert Cryan and Mary Anne Cryan of Boyle, County Roscommon, Ireland. He had two sisters, Mary Anne and Belinda, two half brothers, Peter, (also a doctor), John, and a half sister, Bridget. He was married to Mary Whitty, daughter of Nicholas and Mary Whitty, and had one son, a writer, Robert William Whitty Cryan. Cryan died at age 54 at his home in Dublin on 17 February 1881 and left a "considerable fortune" to his family. Cryan is buried at Glasnevin Cemetery in Dublin.