The Great Northern Railway (Ireland) T class were 4-4-2T Atlantic locomotives built by Beyer, Peacock and Company in 1913. Five of this type were built. They were later rebuilt with superheaters as class T1.

As the T1 class, they featured 18 x 24 inch or 18½ x 24 inch cylinders with 5 foot 9 inch wheels, built to 5 feet 3 inches gauge.