Rank by time in office
| Rank | No. | Officeholder | Portrait | Party | District | Assumed office | Left office | Time in office (term) | Time in office (total) | Election wins | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. | 19th | Sir David Brand (1912–1979) KCMG |  | Liberal | MLA for Greenough (1945–1975) | 2 April 1959 | 3 March 1971 |  | 11 years, 335 days | 1959 1962 1965 1968 | |
| 2. | 1st | Sir John Forrest (1847–1918) GCMG |  | Pro-Forrest | MLA for Bunbury (1890–1901) | 29 December 1890 | 15 February 1901 | | 10 years, 48 days | 1890 1894 1897 | |
| 3. | 14th | Philip Collier (1873–1948) |  | Labor | MLA for Boulder (1905–1948) | 16 April 1924 | 24 April 1930 | 6 years, 8 days | 9 years, 126 days | 1924 1927 1933 1936 | |
| 24 April 1933 | 20 August 1936 | 3 years, 118 days | |||||||||
| 4. | 15th | John Willcock (1879–1956) |  | Labor | MLA for Geraldton (1917–1947) | 20 August 1936 | 31 July 1945 | | 8 years, 345 days | 1939 1943 | |
| 5. | 29th | Colin Barnett (1950– ) |  | Liberal | MLA for Cottesloe (1990–2018) | 23 September 2008 | 17 March 2017 | | 8 years, 175 days | 2008 2013 | |
| 6. | 26th | Richard Court (1947– ) AC |  | Liberal | MLA for Nedlands (1982–2001) | 16 February 1993 | 10 February 2001 | | 7 years, 360 days | 1993 1996 | |
| 7. | 13th | Sir James Mitchell (1866–1951) GCMG |  | Nationalist | MLA for Northam (1905–1933) | 17 May 1919 | 16 April 1924 | 4 years, 335 days | 7 years, 335 days | 1921 1930 | |
| 24 April 1930 | 24 April 1933 | 3 years, 0 days | |||||||||
| 8. | 21st | Sir Charles Court (1911–2007) AK KCMG OBE |  | Liberal | MLA for Nedlands (1953–1982) | 8 April 1974 | 25 January 1982 | | 7 years, 292 days | 1974 1977 1980 | |
| 9. | 30th | Mark McGowan (1967– ) |  | Labor | MLA for Rockingham (1996–2023) | 17 March 2017 | 8 June 2023 | | 6 years, 83 days | 2017 2021 | |
| 10. | 18th | Albert Hawke (1900–1986) |  | Labor | MLA for Northam (1933–1968) | 23 February 1953 | 2 April 1959 | | 6 years, 37 days | 1953 1956 | |
| 11. | 17th | Sir Ross McLarty (1891–1962) KBE MM |  | Liberal | MLA for Murray-Wellington (1930–1950) Murray (1950–1962) | 1 April 1947 | 23 February 1953 | | 5 years, 328 days | 1947 1950 | |
| 12. | 23rd | Brian Burke (1947– ) | Labor | MLA for Balga (1983–1988) | 25 February 1983 | 25 February 1988 | | 5 years, 0 days | 1983 1986 | ||
| 13. | 27th | Dr Geoff Gallop (1951– ) AC |  | Labor | MLA for Victoria Park (1986–2006) | 16 February 2001 | 25 January 2006 | | 4 years, 343 days | 2001 2005 | |
| 14. | 10th | John Scaddan (1876–1934) CMG |  | Labor | MLA for Brown Hill-Ivanhoe (1911–1916) | 7 October 1911 | 27 July 1916 | | 4 years, 294 days | 1911 1914 | |
| 15. | 8th | Sir Newton Moore (1870–1936) KCMG |  | Ministerial | MLA for Bunbury (1904–1911) | 7 May 1906 | 16 September 1910 | | 4 years, 132 days | 1908 | |
| 16. | 20th | John Tonkin (1902–1995) AC |  | Labor | MLA for Melville (1950–1977) | 3 March 1971 | 8 April 1974 | | 3 years, 66 days | 1971 | |
| 17. | 25th | Dr Carmen Lawrence (1948– ) |  | Labor | MLA for Glendalough (1989–1994) | 12 February 1990 | 16 February 1993 | | 3 years, 4 days | ||
| 18. | 28th | Alan Carpenter (1957– ) |  | Labor | MLA for Willagee (1996–2009) | 25 January 2006 | 23 September 2008 | | 2 years, 242 days | ||
| 19. | 31st | Roger Cook (1965– ) |  | Labor | MLA for Kwinana (2008–) | 8 June 2023 | Incumbent | | 2 years, 46 days [1] | 2025 | |
| 20. | 5th | Sir Walter James (1863–1943) KCMG KC |  | Opposition | MLA for East Perth (1894–1904) | 1 July 1902 | 10 August 1904 | | 2 years, 40 days | ||
| 21. | 9th | Frank Wilson (1866–1951) CMG |  | Nationalist | MLA for Sussex (1904–1917) | 16 September 1910 | 7 October 1911 | 1 year, 21 days | 1 year, 357 days | ||
| Liberal (WA) | 27 July 1916 | 28 June 1917 | 336 days | ||||||||
| 22. | 24th | Peter Dowding (1943– ) SC |  | Labor | MLA for Maylands (1986–1990) | 25 February 1988 | 12 February 1990 | | 1 year, 352 days | 1989 | |
| 23. | 11th | Sir Henry Lefroy (1854–1930) KCMG |  | Nationalist | MLA for Moore (1911–1921) | 28 June 1917 | 17 April 1919 | | 1 year, 293 days | 1917 | |
| 24. | 16th | Frank Wise (1897–1986) AO |  | Labor | MLA for Gascoyne (1933–1951) | 31 July 1945 | 1 April 1947 | | 1 year, 244 days | ||
| 25. | 22nd | Ray O'Connor (1926–2013) |  | Liberal | MLA for Mount Lawley (1962–1984) | 25 January 1982 | 25 February 1983 | | 1 year, 31 days | ||
| 26. | 6th | Henry Daglish (1866–1920) |  | Labor | MLA for Subiaco (1901–1911) | 10 August 1904 | 25 August 1905 | | 1 year, 15 days | ||
| 27. | 3rd | George Leake (1856–1902) CMG |  | Opposition | MLA for West Perth (1901–1902) | 27 May 1901 | 21 November 1901 | 178 days | 1 year, 3 days | 1901 | |
| 23 December 1901 | 1 July 1902 | 190 days | |||||||||
| 28. | 7th | Sir Cornthwaite Rason (1858–1927) |  | Ministerial | MLA for Guildford (1901–1906) | 25 August 1905 | 7 May 1906 | | 255 days | 1905 | |
| 29. | 2nd | George Throssell (1840–1910) CMG |  | Pro-Forrest | MLA for Northam (1890–1904) | 15 February 1901 | 27 May 1901 | | 101 days | ||
| 30. | 4th | Alf Morgans (1850–1933) |  | Ministerial | MLA for Coolgardie (1897–1904) | 21 November 1901 | 23 December 1901 | | 32 days | ||
| 31. | 12th | Sir Hal Colebatch (1872–1953) CMG |  | Nationalist | Member of the Legislative Council (1912–1923) | 17 April 1919 | 17 May 1919 | | 30 days |
- ↑ Roger Cook's time in office as of 24July2025