The Old Union School is a historic school building at 504 Old Union Road in Birdell, Arkansas. It is a single-story wood frame Plain Traditional structure, with a corrugated metal gable roof and a stone foundation. Built in 1913, it is one of the few older structures in Birdell, and the only one-room schoolhouse in southwestern Randolph County. The building was used as a school until 1941, and saw only occasional use for other community purposes until 1991, when it underwent a major restoration. It is now used as a community hall.The building was listed on the National Register of Historic Places in 1993.
