List of Premiers of Tasmania by time in office Rank by time in office Rank by time in office

| Rank_ | Premier_ | Party_ | Assumed_Office_ | Left_Office_ | TOTAL_Time_in_Office_ |
|---|---|---|---|---|---|
| 1. | Sir Robert Cosgrove | Labor | 18 December 1939 | 18 December 1947 | 18 years, 182 days |
| 1. | Sir Robert Cosgrove | Labor | 25 February 1948 | 26 August 1958 | 18 years, 182 days |
| 2. | Eric Reece | Labor | 26 August 1958 | 26 May 1969 | 13 years, 240 days |
| 2. | Eric Reece | Labor | 3 May 1972 | 31 March 1975 | 13 years, 240 days |
| 3. | Robin Gray | Liberal | 26 May 1982 | 29 June 1989 | 7years, 34days |
| 4. | Sir Walter Lee | Commonwealth Liberal | 15 April 1916 | 12 August 1922 | 6 years, 191 days |