In 1889, one hundred and thirty eight citizens of St. Marys area petitioned the government asking for incorporation as a municipality. The Government, with Sir Henry Parkes as Premier, agreed to this request and in a proclamation dated 3 March, 1890 the Municipality of St Marys was constituted. The first municipal election was announced in the Government Gazette on Thursday 3 April 1890, to be held on 5 May. The following citizens were elected:-
- William Garner, Mayor
- George Turner
- James Hope
- William Carberry
- Charles Gilbert
- William Beecroft
Henry Wake was appointed the first Town Clerk.
Meetings were initially held monthly in the Protestant Hall, Great Western Road, St Marys.
In 1894, there was a further proclamation with new boundaries to the south, thus, enlarging the municipality. In 1906, there was a further addition in the southern section.
H Wake 1890 -1906
J S Paskin 1907
W H Wrench 1908-1928
James Heel 1929 -1931
Henry Joseph Charles 1932 -1933
Albert Victor Sutton 1934-1942
Evan Forrester Ross 1943 – 1948
In November 1907, St Marys Municipal Council was divided into wards:
County Of Cumberland, parishes of Londonderry and Claremont, commencing at the intersection of South Creek with the Orphan School or Mulgoa Road and bounded by the centre of that road from Camden to Richmond northerly to the intersection of the westerly prolongation of the northern boundary of portion 112, parish of Londonderry; hence by a line, part of which forms the northern of that position and positions of 113 and 116 Easterly to the centre of South Creek, and by the centre of that creek upwards to the point of commencement.
County of Cumberland, Parishes of Melville and Rooty Hill, commencing at the intersection of Rope’s creek and the road from Windsor to St. Marys and bounded by the lines along the centre of that road, Mamre Road and the road to Luddenham southerly to South Creek, by the centre of that creek downwards to its intersection with the westerly prolongation of the northern boundary position 112, parish of Rooty Hill, hence by a line and the northern boundary of that position easterly to the centre of Rope’s Creek, and by the centre of that Creek to the point of commencement.
County of Cumberland, parishes of Melville and Rooty Hill, commencing at the intersection of Rope’s Creek and the road from Windsor to St. Marys, and bounded by lines along the centre of that road, Mamre Road and the road to Luddenham southerly to South Creek, by the centre of that creek upwards, the centre of Orphan School or Mulgoa Road easterly, to the eastern boundary.
St Marys had been a Municipality for 40 years before an official home for council was built in Mamre Road. Finally in December 1933 the new building was opened. Designed by Sydney architect Mr Carfrea it was of semi-colonial style with a spacious council room with polished maple joinery and polished tallow wood floors. After the amalgamation of the local councils in 1949 the building became the St Marys Branch Library. In 1979 when the library moved to new premises, this building became the home of the St Marys Community Arts.“New Council Chambers Official Opening at St. Marys: A fine structure “, Nepean Times, 9 December 1933 p. 3.
St Marys Council Chambers
On 1 January 1949, St Marys Municipal Council amalgamated with Penrith Municipal Council.