Pannonia Prima was an ancient Roman province. It was formed in the year 296, during the reign of Emperor Diocletian. Previously, it was a part of the province of Pannonia Superior, which, along with Pannonia Inferior, was gradually divided into four administrative units: Pannonia Prima, Pannonia Secunda, Valeria, and Savia. This transition was completed by the time of Constantine. According to the Notitia Dignitatum, Pannonia Prima was governed by a Praeses.