Bicester, town (parish), Cherwell district, administrative and historic county of Oxfordshire, southeastern England. It lies in farming country on the northern edge of the reclaimed marsh of Ot Moor.
An Augustinian priory (1182) was dissolved there in 1538 and is now in ruins. Richard II granted the town a fair and a market, and in 1440 an additional market was granted. In the 16th century a cattle market was also established. The church contains examples of Saxon, Norman, and later architectural styles.
Bicester is the centre of a traditional fox hunt dating from the 18th century, now known as the Bicester and Warden Hill Hunt. A nearby large army ordnance depot has brought many employees into the area, and industry has expanded. Pop. (2001) 28,672; (2011) 30,854.