Spider Identification
Ontario Spider ID Guide
Not sure what spider you found? This guide covers the species Ontario homeowners encounter most - what they look like, where they live, whether they bite, and what to do about them.
Ontario is home to over 800 spider species, though only a handful are regularly encountered in and around homes. Most Ontario spiders are harmless - they are efficient predators of the insects that would otherwise be living in your home alongside you. The concern for most homeowners is less about danger and more about the discomfort of sharing your living space with them.
This guide covers the species you are most likely to find: the ones responsible for the cobwebs in your basement, the large spider on the garage floor in September, the pale spider on the wall at night, and the enormous spider on the dock. Click any species for full identification details, bite risk, seasonal activity, and habitat information.
Which Spider is Dangerous in Ontario?
The vast majority of Ontario spiders are not medically dangerous. The only spider in Ontario with genuinely medically significant venom is the northern black widow (Latrodectus variolus), which is rare and restricted to extreme southern Ontario - primarily the Niagara Peninsula and the Carolinian forest zone.
The yellow sac spider is the species most likely to bite Ontario homeowners unprovoked and is responsible for the majority of spider bites reported in the province - but its bite, while painful, is not medically dangerous.
The brown recluse spider does not live in Ontario. If you think you spotted one, this guide explains what Ontario species are commonly mistaken for it.
Get Rid of Them
Professional Spider Control Across Ontario
Identified the spider - now want it gone? Spider Squad's exterior perimeter treatment eliminates spiders and the insects they feed on. Find your region below.
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