| Official Name: | Mystery Lake |
| Settlement Type: | Local government district |
| Pushpin Map: | Canada Manitoba |
| Pushpin Map Caption: | Location of Mystery Lake in Manitoba |
| Subdivision Type: | Country |
| Subdivision Name: | Canada |
| Subdivision Type1: | Province |
| Subdivision Name1: | Manitoba |
| Subdivision Type2: | Region |
| Subdivision Name2: | Northern Manitoba |
| Subdivision Type3: | Census division |
| Subdivision Name3: | No. 22 |
| Leader Title2: | (Thompson) |
| Leader Name2: | Steve Ashton (NDP) |
| Leader Title3: | MP (Churchill) |
| Leader Name3: | Niki Ashton (NDP) |
| Established Title: | Established |
| Established Date: | [1] |
| Unit Pref: | Metric |
| Population As Of: | 2016 |
| Population Footnotes: | [2] |
| Population Total: | 0 |
| Population Density Km2: | 0.0 |
| Timezone: | CST |
| Utc Offset: | −6 |
| Timezone Dst: | CDT |
| Utc Offset Dst: | −5 |
| Coordinates: | 55.55°N -98°W |
| Postal Code Type: | Postal code |
| Postal Code: | R8N |
| Area Code: | 204 |
| Blank Name: | Highways |
| Blank Info: | PR 280 |
| Area Land Km2: | 3,460.46 |
Mystery Lake is a local government district (LGD) in northern Manitoba. It surrounds the city of Thompson, although most of its territory lies to the southwest and south of the city. It is named after Mystery Lake, a lake located in the northeast section of the LGD, northeast of Thompson.
In the 2021 Census of Population conducted by Statistics Canada, Mystery Lake had a population of 0 living in 0 of its 0 total private dwellings, no change from its 2016 population of 0. With a land area of, it had a population density of in 2021.[3]