SEK (Sidirodromoi Ellinikou Kratous, Hellenic State Railways) Class Λβ (or Class Lb; Lambda-beta) is a class of 16 2-10-0 steam locomotives, ex-WD Austerity 2-10-0s purchased after the Second World War. All of them were previously stabled in Egypt and were transported to Greece, as part of the UNRRA mission in Greece (arrived at Thessaloniki port on 16 January 1946). They were given the class letters "Λβ" and numbers 951–966.