Lloyd Cassel Douglas (August 27, 1877 - February 13, 1951) was a noteworthy American minister and author. He was born in Columbia City, Indiana and died in Los Angeles, California.

Douglas was one of the most popular American authors of his time, although he didn't write his first novel until he was 50 yrs. of age.

He was the son of a minister, and after receiving the A.M. degree from Wittenberg College in Springfield, Ohio, in 1903, he was ordained in the Lutheran ministry. He served in pastorates in North Manchester, Indiana, Lancaster, Ohio, and Washington, D.C.. From 1911 to 1915, he was director of religious work at the University of Illinois, Urbana. The next six years, he was minister of The First Congregational Church in Ann Arbor, Michigan, from there moving to Akron, Ohio, and serving as the Sr. Minister of the First Congregational Church of Akron from 1920 - 1926 then to Los Angeles, California and finally to the St. James United Church at Montreal, Quebec, from which pulpit he retired to write.

His written works were of a moral, didactic , and distinctly religious tone. His first novel, The Magnificent Obsession, published in 1929, was an immediate and sensational success. Critics held that his type of fiction was in the tradition of the great religious writings of an earlier generation, such as, Ben-Hur and Quo Vadis.

Douglas then wrote Forgive Us Our Trespasses; Green Light; White Banners; Disputed Passage; Doctor Hudson's Secret Journal; The Robe, and The Big Fisherman. The Robe sold more than 2 million copies, without any reprint edition. Douglas sold the motion picture rights to this story, though the film, starring Richard Burton, was not released until 1953, after Douglas's death.

His own unhappy experience of filming prompted Douglas, when he produced The Big Fisherman as the sequel to The Robe, to stipulate that The Big Fisherman would be his last novel, and that he would not permit it to be made into a motion picture, used over the radio, condensed or serialised.