Regional field guide
Snakes in Ontario
10+ snake species have verified records in Ontario, including 1 venomous. Pick your county below to see exactly which snakes live near you.

Snakes of Ontario
Ontario has 17 recorded snake species, of which 1 is venomous. That low count reflects Canada's cold northern climate, which sharply limits how many snake species can survive this far north.
Cold winters are the main constraint. Snakes are ectotherms and cannot stay active through long freezing seasons, so Ontario species spend months in hibernation, often gathering in communal dens below the frost line to share scarce shelter and survive until spring. Garter snakes, the most cold-tolerant snakes in the Americas, are the most widespread here, alongside harmless species such as redbelly snakes, ringneck snakes, and watersnakes.
The one venomous species in Ontario is the eastern massasauga, a small rattlesnake found in limited areas. It is shy and rarely encountered, but you should still never handle a wild snake. Every other snake in the province is harmless to people. If a venomous bite ever occurs, do not attempt first aid yourself; call US Poison Control at 1-800-222-1222 or local emergency services and get to emergency care right away.
Venomous snakes in Ontario
Most commonly seen
- Common Garter SnakeCommonly seen
- Common WatersnakeCommonly seen
- DeKay's BrownsnakeCommonly seen
- Red-bellied SnakeCommonly seen
- Eastern MilksnakeCommonly seen
- Eastern MassasaugaCommonly seen
- Common Ribbon SnakeCommonly seen
- Smooth GreensnakeCommonly seen
- Ring-necked SnakeCommonly seen
- Eastern FoxsnakeCommonly seen
- Gray RatsnakeCommonly seen
- Eastern Hognose SnakeCommonly seen
Counties in Ontario
53 listed- Algoma7
- Brant9
- Bruce9
- Chatham-Kent9
- Cochrane4
- Dufferin5
- Durham6
- Elgin6
- Essex9
- Frontenac11
- Greater Sudbury6
- Grey8
- Haldimand-Norfolk11
- Haliburton8
- Halton8
- Hamilton9
- Hastings9
- Huron10
- Kawartha Lakes10
- Kenora2
- Lake Erie13
- Lake Hurron13
- Lake Ontario10
- Lake Superior3
- Lambton12
- Lanark10
- Leeds and Grenville11
- Lennox and Addington8
- Manitoulin10
- Middlesex12
- Muskoka11
- Niagara10
- Nipissing9
- Northumberland6
- Ottawa9
- Oxford7
- Parry Sound12
- Peel5
- Perth4
- Peterborough9
- Prescott and Russell3
- Prince Edward7
- Rainy River2
- Renfrew7
- Simcoe11
- Stormont, Dundas and Glengarry3
- Sudbury9
- Thunder Bay6
- Timiskaming4
- Toronto9
- Waterloo8
- Wellington8
- York5
Snakes in Ontario: FAQ
- Are there venomous snakes in Ontario?
- Yes. 1 venomous snake species has verified records in Ontario, including Eastern Massasauga. Most snakes in Ontario, however, are harmless.
- How many snake species live in Ontario?
- 10+ snake species have verified records in Ontario, of which 1 is venomous.
- What is the most commonly seen snake in Ontario?
- The Common Garter Snake is the most frequently reported snake in Ontario, based on verified wildlife observations.
- What should I do if I see a venomous snake in Ontario?
- Keep your distance and do not try to catch or kill it. Most bites happen when people handle or corner a snake. If someone is bitten, contact local emergency services or poison control immediately.