John Eric Langdon-Davies (18 March 1897 – 5 December 1971) was a British author and journalist.
He was a war correspondent during the Spanish Civil War and the Russo-Finnish war.
As a result of his experiences in Spain, he founded the Foster Parents' Scheme for refugee children in Spain, now a huge international organisation called Plan.
He was awarded the MBE for services to the Home Guard.
Author of books on military, scientific, historical and Spanish (including Catalan) subjects, Langdon-Davies has been described as "an accomplished war correspondent" and "a brilliant populariser of science and technology".