Great Coxwell Barn is a historic barn located in Great Coxwell, Oxfordshire, England. Built in the 13th century, it is a fine example of medieval architecture and was originally part of a larger monastic estate associated with Beaulieu Abbey. The barn is notable for its impressive size and construction, featuring a thatched roof and large wooden beams. The barn is recognized as a scheduled ancient monument and is managed by English Heritage. It serves as a reminder of the agricultural practices of the medieval period and is often visited by those interested in history and architecture.