The NBR K class is a class of 4-4-0 steam locomotive of the North British Railway. The first batch (later LNER Class D26) was designed by Matthew Holmes in 1902 and had 6-foot-6-inch (1.981 m) driving wheels for express passenger work. Three more batches (later LNER Classes D32/D33/D34) were designed by William P. Reid with 6-foot-0-inch (1.829 m) driving wheels for mixed traffic work. This included perishable goods, such as fish from Mallaig and Aberdeen.