Cholsey Abbey was an Anglo-Saxon nunnery in Cholsey in what is now the English county of Oxfordshire (formerly Berkshire), which was founded in 986.

After King Edward the Martyr was murdered, his stepmother, Ælfthryth, was implicated in the crime. Edward's death had allowed Ælfthryth's son, Æthelred the Unready, to ascend to the throne and become King of England. Both Ælfthryth and Æthelred were instrumental in establishing Cholsey Abbey: an act of expiation for Edward's death.

Following the Danish attack on Wallingford in 1006, it is thought that the invaders burned the nunnery to the ground. However, some ruins may have survived and were later rebuilt as St Mary's Church, Cholsey (the parish church), where Anglo-Saxon masonry survives in the tower.

The site, nothing of which remains on the ground, lies immediately north-west of large village with its many amenities.

• Royal Berkshire History: Cholsey
• British History Online: Victoria County History of Berkshire: The Abbey of Reading (mentioning Cholsey Abbey)

51°34′44″N 1°09′32″W / 51.5788°N 1.1590°W / 51.5788; -1.1590