Career profile
Bill Dunnion
Chief Information Security Officer (CISO), Mitel
- Current role, per sources checked 23 October 2026
- April 2024
Bill Dunnion is the Chief Information Security Officer of Mitel, appointed in April 2024.
Career path
Dunnion holds a degree in mechanical engineering from Queen's University in Kingston, Ontario, and started his career in that field before moving into product marketing.
His first stint at Mitel, in the late 1990s, was in product marketing, where he worked alongside colleagues who remain with the company.
The first half of his career was spent in telecommunications; the shift to voice-over-IP gave him his entry into IT and then security, and the second half of his career has been in IT security, spanning sales, marketing, product management and delivery.
He went on to hold IT and cybersecurity leadership positions at Bell Canada, 2Keys Security Solutions and Calian.
At Calian, he served as Senior Director of Corporate Cybersecurity, where he built and operated the company's corporate cybersecurity program, operationalized it within the NIST framework, and oversaw compliance with ISO and SOC2 standards.
Mitel announced Dunnion's appointment as CISO in April 2024, a role in which he oversees the company's information security strategy, security architecture and security standards compliance, and assesses, develops and implements security best practices across the business.
"I am very excited to be joining Mitel to take on this important role," said Dunnion.
Since stepping into the role, he has guided Mitel through ISO compliance efforts and the integration of Unify.
He also serves as volunteer chair of the Canadian Cyber Forum in Ottawa.
Public talks and published work
While at Calian, Dunnion wrote about the hazards of using AI and machine learning tools without understanding the risks, covering data retention and ownership, transparency, privacy, and access control, in an article published on the CIO Association of Canada website.
He discussed his multidisciplinary path into cybersecurity leadership and Mitel's approach to turning security into a business enabler in an interview with SafetyDetectives, republished on Mitel's site.
On the We're In! cybersecurity podcast, Dunnion discussed precedent-setting cases in which CISOs and boards of directors have been held personally liable, privacy legislation including GDPR and Canada's Bill C-26, and the idea that security requirements should carry the same weight as functional requirements in product development.
