| Saint-Janvier-de-Joly | |
| Settlement Type: | Municipality |
| Pushpin Map: | Canada Southern Quebec |
| Pushpin Map Caption: | Location in southern Quebec. |
| Coordinates: | 46.4833°N -111°W |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Type2: | Region |
| Subdivision Name2: | Chaudière-Appalaches |
| Subdivision Type3: | RCM |
| Subdivision Name3: | Lotbinière |
| Established Title1: | Constituted |
| Established Date1: | January 1, 1944 |
| Leader Title: | Mayor |
| Leader Name: | Bernard Fortier |
| Leader Title1: | Federal riding |
| Leader Name1: | Lotbinière— Chutes-de-la-Chaudière |
| Leader Title2: | Prov. riding |
| Leader Name2: | Lotbinière-Frontenac |
| Area Total Km2: | 111.40 |
| Area Land Km2: | 109.88 |
| Population Total: | 1079 |
| Population As Of: | 2021 |
| Population Density Km2: | 9.8 |
| Population Blank1 Title: | Pop 2016-2021 |
| Population Blank1: | 9.7% |
| Population Blank2 Title: | Dwellings |
| Population Blank2: | 500 |
| Timezone: | EST |
| Utc Offset: | −5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | −4 |
| Postal Code Type: | Postal code(s) |
| Postal Code: | G0S 1M0 |
| Area Code: | 418 and 581 |
| Blank Name: | Highways |
Saint-Janvier-de-Joly is a municipality in Lotbinière Regional County Municipality in Quebec, Canada. It is part of the Chaudière-Appalaches region and had a population is 1,079 as of 2021.
It is named after Reverend Janvier Lachance, a missionary, who served the parish from 1914 to 1926. "Joly" honours Quebec Premier Henri-Gustave Joly de Lotbinière, the owner of the seigneurie of Lotbinière, which inluded Saint-Janvier-de-Joly.
The post office, opened in 1924, is called Joly, name under which the municipality is most commonly known.