The site of the church has long been associated with Christianity, going back perhaps as far as 566 when St Moluag is said to have founded a religious community there.

There was a bishopric on the site in the eleventh and twelfth centuries, prior to it being moved to Aberdeen in the reign of King David I.

Mortlach Parish Church is built in a T-plan, and much of the existing structure dates to the nineteenth and twentieth centuries,[1] but it incorporates substantial amounts of mediaeval and post-mediaeval fabric.

[2] The nave, which reflects the plan of the original thirteenth-century building, is rectangular,[3] oriented east-west,[4] with a nineteenth-century aisle projecting from the north side.

[1] At the east end of the nave is a raised chancel, which features a marble font, and wooden pulpit and communion table dating from the 1930s.

It is irregularly shaped and surrounded by rubble walls with spear-head railing, and contains tombstones dating from the seventeenth, eighteenth, nineteenth and twentieth centuries.

[9] The stone is thought to date from some point between the seventh and ninth centuries, and is traditionally believed to commemorate a battle, but this is not certain.

[5] Malcolm II is also believed to have established a bishopric at Mortlach,[5] and scholars generally accept that at least three bishops were based there prior to 1140.