| Election Name: | 1858 New South Wales colonial election |
| Country: | New South Wales |
| Flag Image: | Flag of the United Kingdom.svg |
| Type: | parliamentary |
| Ongoing: | no |
| Previous Election: | 1856 New South Wales colonial election |
| Previous Year: | 1856 |
| Next Election: | 1859 New South Wales colonial election |
| Next Year: | 1859 |
| Seats For Election: | All 54 seats in the New South Wales Legislative Assembly 28 Assembly seats were needed for a majority |
| Election Date: | 13 January 1858 – 12 February 1858 |
| Leader1: | Charles Cowper |
| Leaders Seat1: | Sydney City |
| Map Size: | 300px |
| Premier | |
| Before Election: | Charles Cowper |
| After Election: | Charles Cowper |
The 1858 New South Wales colonial election was held between 13 January and 12 February 1858. This election was for all of the 54 seats in the New South Wales Legislative Assembly and it was conducted in 18 single-member constituencies, 13 2-member constituencies, two 3-member constituencies and one 4-member constituency, all with a first past the post system. Suffrage was limited to adult white males. The previous parliament of New South Wales was dissolved on 19 December 1857 by the Governor, Sir William Denison, on the advice of the Premier, Charles Cowper.
There was no recognisable party structure at this election; instead the government was determined by a loose, shifting factional system.
| Date | Event | |
|---|---|---|
| 19 December 1857 | The Legislative Assembly was dissolved, and writs were issued by the Governor to proceed with an election. | |
| 12 January to 1 February 1858 | Nominations for candidates for the election closed. | |
| 13 January to 12 February 1858 | Polling days. | |
| 23 March 1858 | Opening of new Parliament. |
|}