Public health officials with the Northern Inter-Tribal Health Authority (NITHA) declared the outbreak Monday afternoon.
They said they are an increasing number of confirmed coronavirus cases in the community linked to private family gatherings on Dec. 25 and 31.
Officials said contact tracing is underway and are advising anyone who was at either event to immediately self-isolate if they have had or currently have COVID-19 symptoms.
They should also call HealthLine 8-1-1 or the community health clinic to arrange for assessment and testing, NITHA said.
Individuals who were at the events but who are not experiencing symptoms should self-monitor for 14 days from the date of the last exposure.
As of Jan. 4, there were 16 active cases in Stanley Mission, with one person in hospital.
Stanley Mission recently enacted a number of measures to stop the spread of COVID-19 in the community.
A curfew between 11 p.m. and 7 a.m. is in place and only essential travel is permissible.
“There will be no traffic in or out of town for non-essential reasons,” said a statement from the Amachewespimawin First Nation.
“Stanley Mission residents will only be permitted to leave the community and return for medical trips deemed time-sensitive from the health care team.”
Read more: COVID-19 outbreaks in Saskatchewan
No one living outside the community is allowed in Stanley Mission unless it is for compassionate reasons, which will be determined by “the roadblock supervisor in collaboration with the health care team.”
Residents returning to Stanley Mission are required to have their temperature taken at a check stop. Those with a temperature over 37.8C are required to self-isolate immediately at their home and contact the health clinic.
Those refusing to take a temperature check are not allowed in the community, officials said.
“The restrictions are being implemented for the safety of the community,” the statement said.
It is not known how long the measures will remain in place.
Stanley Mission is roughly 450 kilometres north of Saskatoon.