| Cabinet Name: | First O'Shanassy ministry |
| Cabinet Number: | 2nd |
| Jurisdiction: | Victoria, Australia |
| Date Formed: | 11 March 1857 |
| Date Dissolved: | 29 April 1857 |
| State Head Title: | Monarch |
| Government Head Title: | Premier |
| Government Head: | John O'Shanassy |
| State Head: | Victoria |
| Governor: | Sir Henry Barkly |
| Current Number: | 7 |
| Political Party: | Independent |
| Predecessor: | First Haines ministry |
| Successor: | Second Haines ministry |
| Flag: | File:Flag of Victoria (1870-1877).svg |
| Flag Border: | true |
| Cabinet Type: | ministry |
The First O'Shanassy Ministry was the 2nd ministry of the Government of Victoria.[1] It was led by the Premier of Victoria, John O’Shanassy, with the swearing in of the ministry occurring on 11 March 1857.[2]