St Andrew's Cathedral is of aesthetic significance for the high quality of the Gothic design and detailing of the building. It is one of the major Gothic buildings in Sydney and even though small in comparison to many cathedrals is well executed showing the hand of Blacket. It has strong visual qualities within the Sydney Square precinct. The building has a very fine interior and houses a collection of furniture, fixtures and fittings that date from the time of construction. With the exception of several smaller additions identified as not having significance the buildings form a unified complex which, even though sited on a restricted site provide a group envisaged by Blacket. The cathedral is sited in the major civic and ceremonial precinct in the city and is a key element in the streetscape and townscape of the city. It is a landmark building that is widely recognised and admired by the community. Although altered, the Hill organ is a fine instrument with a very good tonal quality. The organ case and pipework are an important element of the cathedral interior. The addition of the Kinloch organ to the cathedral enhances the music and appearance of the interior.