The Colonial Secretary of Western Australia was one of the most important and powerful public offices in Western Australia, in the time when Western Australia was a British colony. The Colonial Secretary was the representative of the British Colonial Office in Western Australia, and was usually appointed from Britain. He was responsible for all official correspondence between the colony and the Colonial Office. He was at all times a member of the Western Australian Legislative Council and the Executive Council of Western Australia.
After Western Australia gained responsible government in 1890, the office of Colonial Secretary became a ministerial portfolio. The responsibilities of the office changed substantially, and it was no longer such an important role. In 1917 the office of Colonial Secretary was described as being:
Since Western Australia was no longer a British colony after 1901, the office of Colonial Secretary was misnamed after this date. In 1924, the office was renamed to Chief Secretary.
The following is a list of colonial secretaries of Western Australia:
| Colonial Secretary | Period in office | |
|---|---|---|
| Peter Broun | 1828 - 1846 | |
| George Fletcher Moore (acting) | November 1846 - 1847 | |
| May 1847 - 1849 | ||
| Revett Bland (acting) | January 1849 - March 1850 | |
| Thomas Yule (acting) | March 1850 - October 1850 | |
| Charles Alexander John Piesse | October 1850 - March 1851 | |
| Thomas Yule (acting) | March - December 1851 | |
| Thomas Falconer | From March 1851 but never arrived in colony | |
| William Ayshford Sanford | January 1852 - July 1855 | |
| Frederick Barlee | July 1855 - 24 November 1875 (on leave from 24 July 1875) | |
| Anthony O'Grady Lefroy (acting) | 24 July 1875 - 30 August 1877 | |
| Roger Goldsworthy | 30 August 1877 - 7 September 1880 | |
| Edric Gifford | 2 November 1880 - 21 January 1883 | |
| Malcolm Fraser | 5 January 1883 - 28 December 1890 | |
| Matthew Smith (acting) | 8 December 1885 - 18 April 1887 | |
| George Shenton | 29 December 1890 - 11 October 1892 | |
| Stephen Parker | 11 October 1892 - 4 December 1894 | |
| John Forrest | 4 December 1894 - 28 April 1898 | |
| George Randell | 28 April 1898 - 27 May 1901 | |
| Frederick Illingworth | 27 May - 21 November 1901 | |
| Matthew Moss | 21 November - 23 December 1901 | |
| Frederick Illingworth | 23 December 1901 - 30 June 1902 | |
| Walter Kingsmill | 1 July 1902 - 10 August 1904 | |
| George Taylor | 10 August 1904 - 7 June 1905 | |
| John Drew | 7 June - 5 August 1905 | |
| Walter Kingsmill | 25 August 1905 - 7 May 1906 | |
| John Connolly | 7 May 1906 - 7 October 1911 | |
| John Drew | 7 October 1911 - 27 July 1916 | |
| Hal Colebatch | 27 July 1916 - 17 April 1919 | |
| Charles Hudson | 17 April - 17 May 1919 | |
| John Scaddan | 17 May - 25 June 1919 | |
| Frank Broun | 25 June 1919 - 22 August 1922 | |
| Richard Sampson | 22 August 1922 - 16 April 1924 |