Llewellyn Jones was born July 13, 1884 in Castletown in the Isle of Man, Great Britain to John and Katherine Jones. He attended King William's College and the Douglas School of Science. Jones married Susan Warren Wailbus in 1917 and together they had three children: Llewellyn, Cornelia, and George Wilbur. From 1914 to 1932, he was the literary editor of the Chicago Evening Post. During his time as editor, Jones also taught writing as a visiting summer instructor at the University of Chicago in 1924 and 1926; and from 1925 to 1927 he was an instructor of short story writing at Northwestern University. After leaving the Chicago Evening Post, he was editor for Willett, Clark and Company, a Chicago publishing firm. Jones moved to Boston in 1937 to take the position of editor of the Christian Register, but resigned in 1941 due to financial instability and conflict between the Christian Register and the American Unitarian Association.
Jones was a member of the Chicago Literary Club, the Cliff Dwellers of Chicago and PEN, and was President of the Greater Boston American-Scandinavian Forum. He authored books and essays and translated several publications from Danish and Swedish. His books include First Impressions; Essays on Poetry, Criticism, and Prosody (1925); How to Criticize Books (1928); and How to Read Books (1930). Jones was one of thirty-four individuals who signed the 1933 Humanist Manifesto I, written by Roy Wood Sellars and Raymond Bragg. He lived in Cambridge, Massachusetts until his death in 1961.