A by-election was held for the New South Wales Legislative Assembly electorate of Cumberland South Riding on 21 August 1856 because Elias Weekes resigned in August 1856 after winning his appeal against his defeat in Northumberland Boroughs.
| Date | Event | |
|---|---|---|
| 9 April 1856 | Elias Weekes elected at the election for Cumberland (South Riding) | |
| 22 May 1856 | Elias Weekes sworn in as a member for Cumberland (South Riding) | |
| 24 June 1856 | Committee of Elections and Qualifications declared that Elias Weekes had been elected for Northumberland.[1] [2] | |
| 5 August 1856 | Next sitting day of the Legislative Assembly and the report of the Committee of Elections and Qualifications was printed.[3] | |
| Elias Weeks resigned as a member for Cumberland (South Riding).[4] | ||
| 6 August 1856 | Writ of election issued by the Speaker of the Legislative Assembly.[5] | |
| 18 August 1856 | Nominations at Parramatta | |
| 21 August 1856 | Polling day between 9 am and 4 pm. | |
| 27 August 1856 | Return of writ |