Guinness was born in Montpelier House,
Kingstown in Taney, Dublin, Ireland. He was homeschooled by his parents and later at Cheltenham and Exeter under Rev. Dr. Mills and Rev. C. Worthy. He was the grandson of
Arthur Guinness and Olivia Whitmore. His father was John Grattan Guinness (1783–1850), Arthur's youngest son, who was an officer in the
Madras Army of the
East India Company. His mother was Jane Lucretia D'Esterre, whose first husband Captain John Norcot D'Esterre had been killed in a duel in 1815 by
Daniel O'Connell, who remorsefully paid her an
annuity. In 1853 at 17 years old, and somewhat backslidden in his faith, Guinness went to sea. During that year he visited the West Indies, Mexico, Texas, and Caribbean Sea area. He returned to England in 1853. In 1854 he was "sick unto death" when starting for the East Indies. So returning home, he repented and resolved to serve the Master. In January 1856 Guinness entered New College in London under a tutor named Dr. Harris. Possessed of extraordinary talent; his gift was that he spoke the language of the people, not the scholar. He preached much while still a student and in 1857 he was ordained an evangelist and began preaching to large audiences, as well as in the open air. Visited many cities and towns in the British Isles. During this time it is claimed that he was persecuted by Roman Catholics. From 1858 to 1860 he was in Canada and had a part in
A. B. Simpson's conversion. He married Fanny Emma Fitzgerald in October 1860. They had a son named Harry, who was born 2 October 1861, in Toronto, Canada. The Dublin
Daily Express wrote in 1858: ==Later life==