The present parish church of Thormanby dates to the twelfth century. It may have belonged to the Augustinian double monastery at Marton, and was certainly given to the nuns of Marton when they separated to form the Priory of Moxby before 1167. The advowson was shared by the Prioress and the successors of the founder of Marton, Bertram de Bulmer, and remained divided following the Dissolution of the Monasteries in the sixteenth century. By the 1920s it was alternately in the gift of the Cayley and Dawney families.

The church is dedicated to St Mary Magdalene, although there appears to have been some confusion over this, with some early nineteenth century sources giving it as St Mary the Virgin and Thomas Bulmer recording a dedication to All Saints in 1890. The building dates to the twelfth century. A north aisle was added c.1200, but was later taken down. The south porch was added in the eighteenth century and the church tower was building in 1822. The north vestry was added c.1900. The church was repaired in 1955 by York architects Brierley, Syme and Leckenby. There was a Rectory House by 1859.

Today Thormanby is part of the benefice of Brafferton with Pilmoor and Myton on Swale.