Saundby is located SW of Gainsborough, close to the Lincolnshire border. The church consists of chancel, nave, N aisle, S porch and W tower. The only Romanesque feature is the font.

The Domesday Survey listed Saundby among the possessions of the Archbishop of York, but no church was mentioned. A church is known to have existed by the late 13thc. It was partially rebuilt at the beginning of the 15thc. by William Saunderby. The tower and S elevation date from around 1500. The chancel was almost entirely renewed by J. L. Pearson in 1885-6 and the N aisle was rebuilt by W. S. Weatherly & F. E. Jones in 1891-2.

The church is now redundant and in the care of the Churches Preservation Trust.

The font is of unusual design and probably quite late in date, perhaps c.1185.