He was educated at the High School of Dundee, St Andrews University and Oriel College, Oxford, where he graduated with a First in classics and humanities.
Chapman did military service in Salonika during World War I, managing to study the works of Johnson there and continue to write for the Times Literary Supplement.
He himself cited her antiquarian interests as the inspiration of his book collecting career, and her editions of Pride and Prejudice and Northanger Abbey both preceded Chapman’s own.
However, Chapman’s own negligence in acknowledging his wife’s contribution to his Jane Austen edition caused her work to go uncredited until later scholars such as David Gilson, Kathryn Sutherland, and Janine Barchas proved otherwise.
He edited an annotated transcription of her incomplete manuscript of Sanditon, published in 1925 as Fragment of a Novel Written by Jane Austen.