Headland Archaeology (UK) Ltd undertook an archaeological evaluation by trial trenching at Middle Farm, Mixbury, prior to the determination of planning permission for the creation of a poultry unit and associated infrastructure. The trial trenching comprised the second stage of the evaluation programme following on from a geophysical survey, also carried out by Headland, and comprised the excavation of eight trial trenches. The evaluation has confirmed the presence of a polygonal enclosure of likely later prehistoric origin at the north-western limits of the proposed development footprint. The enclosure is recorded on the Oxfordshire Historic Environment Record (MOX4798) and was identified by the geophysical survey. The excavations also revealed a curving ditch and a pit of unknown date, which also corresponded to magnetic anomalies. Overall, the archaeological potential of the proposed development footprint, based on the available evidence, is assessed as low across the majority of the site and moderate to high in the vicinity of the prehistoric enclosure.