Outwood Colliery was a coal mine in Outwood, near Stoneclough in the historic county of Lancashire, England. Originally named Clough Side Colliery, it opened in the 1840s and was the largest colliery in the area. It was owned by Thomas Fletcher & Sons, Outwood Collieries, Stoneclough, Manchester. There were two pits. Coal was transported by a tramway to a depot west of Outwood Road, in Radcliffe, and also by tramway through Ringley Wood to the nearby Manchester, Bolton and Bury Canal. A railway sidings from the nearby East Lancashire Railway Line was located nearby, from the northern end of the colliery. In its heyday the colliery employed over 2000 workers.