| Finnish: Hernesaari | |
| Other Name: | Swedish: Årtholmen |
| Settlement Type: | Helsinki Subdivision |
| Subdivision Type: | Country |
| Subdivision Name: |  Finland |
| Subdivision Type1: | Region |
| Subdivision Name1: | Uusimaa |
| Subdivision Type2: | Sub-region |
| Subdivision Name2: | Greater Helsinki |
| Subdivision Type3: | Municipality |
| Subdivision Name3: | Helsinki |
| Subdivision Type4: | District |
| Subdivision Name4: | Southern |
| Parts Type: | Subdivision regions |
| Parts Style: | para |
| Total Type: | |
| Area Total Km2: | 0.49 |
| Population Total: | 762 |
| Population Density Km2: | 1,555 |
| Postal Code Type: | Postal codes |
| Postal Code: | 00150 |
| Blank Name Sec1: | Subdivision number |
| Blank Info Sec1: | 204 |
| Blank1 Name Sec1: | Neighbouring subdivisions |
| Blank1 Info Sec1: | Punavuori, Eira, Länsisaaret, Jätkäsaari, Länsisatama |
Hernesaari (in Finnish ˈherneˌsɑːri/; Swedish: '''Ärtholmen'''; until 2013 known as Munkkisaari / Munkholmen)[1] is a quarter in Helsinki, Finland.