A roundhouse is a type of locomotive shed which can be found in use on some railways. Most locomotive sheds are rectangular in shape, but in locations where space is constrained, a roundhouse may be used. The design of a round house is akin to a cutaway section of a doughnut, not usually more than 180°, with tracks perpendicular to the rear wall, converging on a central turntable, via which, access to the railway network is provided.
In Ireland, there have been roundhouses at Broadstone Station (Dublin), Portadown, York Road (Belfast) and Clones. The latter is extant as attempts by the army to demolish it with explosives failed. It is not in railway use as the railway line it served closed in 1959. There was also a roundhouse in the Guinness Brewery to house the locomotives on their industrial railway.