Here are leading cybersecurity companies headquartered or strongly rooted in Canada (short summary + what they’re known for). I included reputable sources so you can dive deeper.

Top Canadian cybersecurity companies

1. BlackBerry (Waterloo, ON) — Enterprise endpoint, IoT and embedded security; large-scale corporate and automotive security offerings. Recent corporate moves include sale of some Cylance assets. (BlackBerry.com)

2. eSentire (Waterloo/Cambridge, ON) — Managed Detection & Response (MDR) and threat-hunting provider with global customers and a strong presence in Canada. (eSentire.com)

3. Herjavec Group / Cyderes (Toronto, ON) — Global managed security services provider (MSSP) and SOC operator; Cyderes is the Herjavec Group-managed SOC/MDR brand. Founded by Robert Herjavec, strong in enterprise SOC and incident response. (newswire.ca)

4. Magnet Forensics (Halifax, NS) — Digital forensics and investigation software used by law enforcement and corporate incident responders. (qualysec.com)

5. ThinkOn (Toronto/Canada-wide) — Canadian sovereign cloud and cloud-security services partner; focuses on secure cloud, data residency and compliance for public sector and regulated customers. (ThinkOn.com)

6. Lorica Cybersecurity (Toronto, ON) — Specializes in high-assurance data protection (quantum-resistant / homomorphic encryption approaches) for sensitive cloud workloads. (globenewswire.com)

7. 123Cyber / 123 Enclave (partnerships with Canadian firms) — Canadian-focused cyber services and sovereign cloud solutions for defence/sensitive workloads (example: 123 Enclave with ThinkOn). (ThinkOn.com)

8. Other notable Canadian players and MSSPs to consider

• Local/regional MSSPs and consultancies (many provinces have strong boutique IR/MSSP firms).
• Global MSSPs with large Canadian operations (e.g., Arctic Wolf now owns some BlackBerry Cylance assets and operates heavily in Canada). (reuters.com)

How to pick among them

• If you need continuous monitoring + incident response: look at MDR/MSSP leaders (eSentire, Herjavec/Cyderes, regional MSSPs).
• For endpoint/IoT and embedded security at scale: BlackBerry.
• For forensic investigations: Magnet Forensics.
• For highly regulated / sovereign cloud needs: ThinkOn and Canadian specialist partners.
• For advanced data-protection / quantum-resistant work: Lorica and similar research-focused firms.

Would you like a tailored shortlist (by company size, region in Canada, or service type — e.g., MDR, endpoint, forensics, cloud security)? I can also fetch recent customer reviews, pricing models, or contact pages for any of these companies.