He was born on July 31, 1858, in Honolulu, Hawaii. His father was Asa Goodale Thurston and mother Sarah Andrews. On his father's side he was grandson of Asa and Lucy Goodale Thurston, who were in the first company of American Christian Missionaries to the Hawaiian Islands in 1820. On his mother's side, he was also the grandson of another early missionary, Lorrin Andrews. His father was speaker of the house of representatives of the Kingdom of Hawaii but died when Lorrin was only a year and a half old in December 1859. He then moved to Maui with his mother.
He was fluent in the Hawaiian language and gave himself the Hawaiian nickname Kakina. In 1872, he attended Punahou School, then known as Oahu College, where he played baseball with the sons of Alexander Cartwright (who invented the modern game). He was expelled shortly before graduation. After working as a translator for a law firm and clerk at the Wailuku Sugar Company, he attended law school at Columbia University. He returned to Honolulu in 1881 and became partners in a law firm with William Owen Smith.
He married Margaret Clarissa Shipman (daughter of missionary William Cornelius Shipman (1824–1861) from Hilo, Hawaii and brother of businessman William Herbert Shipman) in February 1884. They had a son Robert Shipman Thurston on February 1, 1888. Margaret died in childbirth on May 5, 1891 (as did the infant). On April 5, 1894, Lorrin Thurston married Harriet Potter of Saint Joseph, Michigan. They had a daughter Margaret Charter (the mother of Thurston Twigg-Smith) in 1895, and a son Lorrin Potter Thurston in 1900. Lorrin Andrews Thurston died on May 11, 1931. In 1919, Robert Thurston married Evelyn M. Scott, and Margaret Charter married William Twigg-Smith.