The tower is the most important architectural feature of the church and the oldest. In Roman York , Bishophill was the site of the civilian settlement. When the tower was built hundreds of years later, much of the stone  was re-used.The stones in the tower are mainly millstone grit and limestone; there are also a few bits of Roman tile.

Like most York churches  the building  covers several centuries. The nave and the north ailse have their origins in the 12th century, the chancel in the 13th and north chapel and south ailse in the 14th. Other points of interest include pre-conquest carved stones near the tower arch and the mediaeval font. There are  four small panels of late 15th century glass in a window on the south side of the chancel. These depict St. Michael, The Blessed Virgin Mary in Glory, an Archbishop holding a pectoral cross, and an Archbishop with a palium.