Sydney Walter Martin "Marten" Cumberland (23 July 1892 – 1972) was a British journalist, novelist and editor.
He also wrote under the pseudonym, Kevin O'Hara.
He specialised in the detective/mystery genre and created the character of Inspector Saturnin Dax, a French policeman.
During World War I, Cumberland served as a radio operator in the Merchant Navy.
After the war, he worked successively for several newspapers and publishing houses as a writer.
He also composed some detective stories for various magazines.
He became a freelance journalist in 1924.
In 1923, Cumberland published his first novel, Loaded Dice, which he co-wrote with B.V.
Shann.
He married Kathleen Walsh in 1928.
In his last years, he moved to Dublin, where he died in 1972.