Baring was the eighth child, and fifth son, of Edward Charles Baring, first Baron Revelstoke, of the Baring banking family, and his wife Louisa Emily Charlotte Bulteel, granddaughter of the second Earl Grey. Born in Mayfair, he was educated at Eton College and Trinity College, Cambridge. After an abortive start on a diplomatic career, he travelled widely, particularly in Russia. He reported as an eye-witness on the Russo-Japanese War for the London Morning Post.

At the start of World War I he joined the Royal Flying Corps, where he served as assistant to Henderson and Trenchard in France. In 1918 Baring served as a staff officer in the Royal Air Force and was appointed OBE. In 1925 Baring received an honorary commission as a wing commander in the Reserve of Air Force Officers. After his death, Trenchard wrote, "He was the most unselfish man I have ever met or am likely to meet. The Flying Corps owed to this man much more than they know or think."

After the war he enjoyed a period of success as a dramatist, and began to write novels. He suffered from chronic illness in the last years of his life; for the final 15 years of his life he was debilitated by Parkinson's Disease.

He was widely connected socially, to some of the Cambridge Apostles, to The Coterie, and to the literary group around G. K. Chesterton and Hilaire Belloc in particular. He was staunch in his anti-intellectualism with respect to the arts, and a convinced practical joker.

Previously an agnostic, he converted to Roman Catholicism in 1909, "the only action in my life which I am quite certain I have never regretted." Speaking from personal experience, however, he once advised Belloc to "never, never, never talk theology or discuss the Church with those outside it. People simply do not understand what you are talking about and they merely (a) get angry and (b) come to the conclusion that one doesn't believe in the thing oneself and that one is simply doing it to annoy."