The Town Hall was built from local Sydney sandstone in the grand Victorian Second Empire style, inspired by the French Second Empire Hotel de Ville in Paris.
The Town Hall has been described as having "lavishly ornamented composition with focal tower and fanciful roofs".
The building consists of the original Town Hall, mayoral suites and town clerk's offices.
These were designed by J. H. Wilson in 1866, having won a civic competition to design a town hall for the rapidly-growing city.
Construction of his initial designs were completed under the architectural direction of Albert Bond in 1869.
Wilson also designed the interior of the original Town Hall meeting room.
The clock tower was completed in 1873 to the design of E. and T. Bradbridge and whose clock was installed in 1884.
The Centennial Hall and associated offices and entrances were designed by Thomas H. Sapsford in 1883, but after his death were completed by architects David McBeath, John Hennessy and George McRae in 1889.

Sydney Town Hall is a monumental brick and stone structure.
The building houses the Sydney City Council Chamber, reception rooms, the Centennial Hall and offices for the Lord Mayor and elected councillors.
It is on four levels referred to as Lower Ground, Ground, First and Second floors and there are some intermediate levels in the area of the stage and organ.
The building was built in two main stages the first being the vestibule and offices (1869-1880) and the second being the two halls (1880-1889).
On the lowest level of the second stage is the Lower Town Hall, main north and south stairs (which extend to the first floor), corridors, backstage facilities, north and south entrances, and ancillary spaces.
The north corridor links via the enclosed colonnade to Town Hall House to the west.
On the lowest level of the first stage, which is about a metre higher, are vaults in the centre, corridors and offices around the outside.

On the ground floor of the second stage is the Main Hall.
This is the main space in the building and is three storeys high.
At the west end is the stage and the organ which is under a proscenium arch and behind which are facilities for performers.
There are galleries on the other three sides accessed from the second floor with clerestory windows above.
On the north and south sides are wide corridors, main stairs, entrances and rooms containing offices and toilets.
The entrances open onto balconies and grand stairs leading to the street.
The main space on the ground floor of the first stage is the Vestibule which is an elaborate two storey space topped by an oval shaped curved glass dome.
The vestibule has wide corridors on three sides and around the perimeter are rooms containing offices and some public spaces.
Centrally located on the eastern side is the octagonal entrance foyer over which is the clock tower.
This leads off the main entrance to the building, the George Street stair.
The Grand Stair is to the north of the foyer and includes a passenger lift.

The Centennial Hall contains the Grand Organ, the world's largest pipe organ with tubular pneumatic action, built from 1886 to 1889 and installed in 1890 by the English firm of William Hill & Son.
The organ possesses one of only two full-length 64′ organ stops in the world (the Contra-Trombone in the pedal).
Before the opening of the Sydney Opera House and its Concert Hall, the Town Hall was Sydney's premier concert hall, and many notable performances took place there.

On the first floor in the second stage are the corridors servicing the galleries in the Main Hall, the north and south stairs, rooms containing offices and toilets.
In the backstage area are performers facilities and there are links on each side to Town Hall House which is west of the Town Hall.
On the first floor in the first stage, on either side of the upper portion of the vestibule are the main spaces on this level; the Council Chamber and the Reception Room.
A corridor to the east of the Vestibule serves these spaces and offices along the east of the building.
The Grand Staircase ends at this level and
The Town Hall was built from local Sydney sandstone in the grand Victorian Second Empire style, inspired by the French Second Empire Hotel de Ville in Paris. The Town Hall has been described as having "lavishly ornamented composition with focal tower and fanciful roofs". The building consists of the original Town Hall, mayoral suites and town clerk's offices. These were designed by J. H. Wilson in 1866, having won a civic competition to design a town hall for the rapidly-growing city. Construction of his initial designs were completed under the architectural direction of Albert Bond in 1869. Wilson also designed the interior of the original Town Hall meeting room. The clock tower was completed in 1873 to the design of E. and T. Bradbridge and whose clock was installed in 1884. The Centennial Hall and associated offices and entrances were designed by Thomas H. Sapsford in 1883, but after his death were completed by architects David McBeath, John Hennessy and George McRae in 1889.
Sydney Town Hall is a monumental brick and stone structure. The building houses the Sydney City Council Chamber, reception rooms, the Centennial Hall and offices for the Lord Mayor and elected councillors. It is on four levels referred to as Lower Ground, Ground, First and Second floors and there are some intermediate levels in the area of the stage and organ. The building was built in two main stages the first being the vestibule and offices (1869-1880) and the second being the two halls (1880-1889). On the lowest level of the second stage is the Lower Town Hall, main north and south stairs (which extend to the first floor), corridors, backstage facilities, north and south entrances, and ancillary spaces. The north corridor links via the enclosed colonnade to Town Hall House to the west. On the lowest level of the first stage, which is about a metre higher, are vaults in the centre, corridors and offices around the outside.
On the ground floor of the second stage is the Main Hall. This is the main space in the building and is three storeys high. At the west end is the stage and the organ which is under a proscenium arch and behind which are facilities for performers. There are galleries on the other three sides accessed from the second floor with clerestory windows above. On the north and south sides are wide corridors, main stairs, entrances and rooms containing offices and toilets. The entrances open onto balconies and grand stairs leading to the street. The main space on the ground floor of the first stage is the Vestibule which is an elaborate two storey space topped by an oval shaped curved glass dome. The vestibule has wide corridors on three sides and around the perimeter are rooms containing offices and some public spaces. Centrally located on the eastern side is the octagonal entrance foyer over which is the clock tower. This leads off the main entrance to the building, the George Street stair. The Grand Stair is to the north of the foyer and includes a passenger lift.
The Centennial Hall contains the Grand Organ, the world's largest pipe organ with tubular pneumatic action, built from 1886 to 1889 and installed in 1890 by the English firm of William Hill & Son. The organ possesses one of only two full-length 64′ organ stops in the world (the Contra-Trombone in the pedal). Before the opening of the Sydney Opera House and its Concert Hall, the Town Hall was Sydney's premier concert hall, and many notable performances took place there.
On the first floor in the second stage are the corridors servicing the galleries in the Main Hall, the north and south stairs, rooms containing offices and toilets. In the backstage area are performers facilities and there are links on each side to Town Hall House which is west of the Town Hall. On the first floor in the first stage, on either side of the upper portion of the vestibule are the main spaces on this level; the Council Chamber and the Reception Room. A corridor to the east of the Vestibule serves these spaces and offices along the east of the building. The Grand Staircase ends at this level and
Sydney Town Hall