| Chamber: | Assembly |
| State: | New York |
| District: | 21 |
| Representative: | Brian Curran |
| Party: | Republican |
| Residence: | Lynbrook |
New York's 21st State Assembly district is one of the 150 districts in the New York State Assembly. It has been represented by Brian Curran since 2023, defeating Judy Griffin. He previously represented the district between 2011 and 2018.
Historically, President Theodore Roosevelt began his political career representing the 21st district from 1882 to 1884, albeit under entirely different lines. The district was previously based in Manhattan; in Roosevelt's time it included the "Silk Stocking District" of the Upper East Side.
District 21 is located entirely within Nassau County. It includes the town of Hempstead, and contains the villages of Lynbrook, Rockville Centre, Malverne, South Hempstead, Baldwin and parts of Freeport, West Hempstead, Oceanside, East Rockaway, Lakeview, Hewlett, Hempstead, Franklin Square, and Valley Stream.