The James Allen Stone Barn is a historic building located on a farm southeast of Earlham, Iowa, United States. Allen acquired 280 acres (110 ha) in 1855, and is thought to have built this barn to house his draft stallions. The single-story, one-room structure is composed of locally quarried rubble stone. The entrance on the east side and a window on the west side both have arched openings. The interior had four stalls for the horses. Frame lean-tos were added to the north and south elevations at a later date. The barn was listed on the National Register of Historic Places in 1987.