Trimdon Limestone Quarry is a Site of Special Scientific Interest in County Durham, England.

The site is an abandoned quarry and exposed to a section of the Ford Formation of Late Permian magnesian limestone.

The site is nationally important for an interpretation of the geological history of the Ford Formation carbonates.

[1] The abandoned quarry workings include an area of floristically-rich magnesian limestone grassland, a habitat which is nationally scarce in Britain, with only an estimated 270 ha remaining.

[1] The site is part of a larger area that is managed by the Durham Wildlife Trust as the Trimdon Grange Quarry nature reserve.