St Mary's Church is a Church of England parish church in Hitchin, Hertfordshire, England.
St Mary's Church is the largest parish church in Hertfordshire, and is remarkably large for a town of the size of Hitchin—this has been cited as evidence of how Hitchin prospered from the wool trade. The present church stands on the site of two previous churches and dates from the 14th and 15th centuries, with its tower dating from around 1190. The church has been Grade I listed since 1951.During the laying of a new floor in the church in 1911, foundations of a more ancient Saxon church building were found. In form, they appear to be a basilican church of a 7th-century type, with a later enlarged chancel and transepts, perhaps added in the 10th century. These may have been the remains of a Benedictine monastery said to have been first on the site and to have been founded by Offa, King of Mercia.
Coordinates 51°56'52.583" N -0°16'38.127" E