Police made the grim discovery around 1 a.m. CST Wednesday in the northeast Saskatchewan town.
The male suspect was tracked to a home in Prince Albert and when police entered the premises at 6:20 a.m, they found him dead, RCMP said.
Police would not say how the man died, but said his death was not a homicide.
A six-month-old baby was found with him. The baby is now being cared for.
Police did not provide the relationship between the man and the woman, but said they were known to each other.
The woman and her children had been reported missing the day before.
RCMP are working to identify those who were killed and notify family members. An update is expected to be provided to reporters at noon.
Tisdale, a town of 3,200 people, is about 211 kilometres northeast of Saskatoon.