A by-election was held for the New South Wales Legislative Assembly electorate of The Tumut on 26 September 1861 because Charles Cowper Jr., the son of then Premier Charles Cowper had been appointed Clerk of the Executive Council in the third Cowper ministry.[1] Such ministerial by-elections were usually uncontested.
| Date | Event | |
|---|---|---|
| 1 September 1861 | Charles Cowper Jr appointed Clerk of the Executive Council. | |
| 2 September 1861 | Writ of election issued by the Speaker of the Legislative Assembly.[2] | |
| 19 September 1861 | Nominations. | |
| 26 September 1861 | Polling day | |
| 10 October 1861 | Return of writ |