# Top 30 critical infrastructure operators in Ottawa

Tamtam tracks 30 critical infrastructure operators headquartered in Ottawa. This list ranks all of them by number of employees on LinkedIn, led by Canada Post / Postes Canada, Canadian Armed Forces | Forces armées canadiennes and City of Ottawa / Ville d’Ottawa. Their median headcount is 1,184. Half of them were founded in 1973 or later.

The companies listed in Ottawa are predominantly public sector entities and essential service providers. They include large government administrations, healthcare institutions, and critical infrastructure operators. Notable examples are Canada Post / Postes Canada, a nationwide postal service; the Canadian Armed Forces, providing defense and security; The Ottawa Hospital, a teaching and research hospital; and Shared Services Canada, modernizing government IT infrastructure.

A significant pattern among these organizations is their role in maintaining public welfare and national operations. Many are federal agencies or government-related entities, such as Canada Border Services Agency and Canadian Coast Guard/Garde côtière canadienne, both focused on national security and maritime services. This concentration reflects Ottawa's status as the capital city.

🇨🇦 Ottawa · 30 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Canada Post / Postes Canada](https://www.tamtam.ai/c/canada-post-postes-canada) (canadapost-postescanada.ca)<br>Nationwide postal service with extensive retail network, delivering parcels and mail to over 17 million Canadian addresses. | Freight and Package Transportation | 🇨🇦 Ottawa | 23,941 |  |
| 2 | [Canadian Armed Forces \| Forces armées canadiennes](https://www.tamtam.ai/c/canadian-armed-forces-forces-armees-canadiennes) (forces.ca)<br>Offering over 100 trades, the organization provides world-class qualifications, competitive salaries, benefits, stability, and exciting opportunities for travel, adventure, and making a difference | Armed Forces | 🇨🇦 Ottawa | 20,412 |  |
| 3 | [City of Ottawa / Ville d’Ottawa](https://www.tamtam.ai/c/city-of-ottawa-ville-d-ottawa) (jobs-emplois.ottawa.ca)<br>A diverse workforce providing essential programs and services for over one million residents in Ottawa, with a focus on customer service and community well-being | Government Administration | 🇨🇦 Ottawa | 9,194 | 1855 |
| 4 | [The Ottawa Hospital](https://www.tamtam.ai/c/the-ottawa-hospital) (ottawahospital.on.ca)<br>Innovative teaching and research hospital providing specialized care, developing new treatments, and improving patient care through community engagement and global impact | Hospitals and Health Care | 🇨🇦 Ottawa | 7,679 | 1998 |
| 5 | [Shared Services Canada \| Services partagés Canada](https://www.tamtam.ai/c/shared-services-canada-services-partages-canada) (canada.ca)<br>Modernizing Government of Canada's IT infrastructure by delivering email, data centre, telecommunication, videoconferencing, and Wi-Fi services to customers | Government Administration | 🇨🇦 Ottawa | 5,161 | 2011 |
| 6 | [Canada Border Services Agency \| Agence des services frontaliers du Canada](https://www.tamtam.ai/c/canada-border-services-agency-agence-des-services-frontaliers-du-canada) (cbsa-asfc.gc.ca)<br>Ensures national security and economic prosperity by managing and monitoring international travel and trade at Canada's borders. | Government Administration | 🇨🇦 Ottawa | 4,369 | 2003 |
| 7 | [Canadian Blood Services](https://www.tamtam.ai/c/canadian-blood-services) (blood.ca)<br>Canada's national organization responsible for ensuring a secure and sustainable supply of blood and organs for transfusion and transplantation | Non-profit Organizations | 🇨🇦 Ottawa | 3,745 | 1998 |
| 8 | [NAV CANADA](https://www.tamtam.ai/c/nav-canada) (navcanada.ca)<br>Operates Canada's civil air navigation service, ensures safe and efficient aircraft movement, provides air traffic control, weather briefings, and navigation aids | Airlines and Aviation | 🇨🇦 Ottawa | 3,416 | 1996 |
| 9 | [Canadian Coast Guard/Garde côtière canadienne](https://www.tamtam.ai/c/canadian-coast-guard-garde-cotiere-canadienne) (canada.ca)<br>A federal agency that operates a civilian fleet and provides maritime services to Canadians, ensuring safe waters, environmental protection, and economic growth | Government Administration | 🇨🇦 Ottawa | 2,892 | 1962 |
| 10 | [CHEO](https://www.tamtam.ai/c/cheo) (cheo.on.ca)<br>A global leader in pediatric health care and research, providing excellence in complex care, education, and community partnership for children and youth | Hospitals and Health Care | 🇨🇦 Ottawa | 2,784 | 1974 |
| 11 | [Bank of Canada](https://www.tamtam.ai/c/bank-of-canada) (bankofcanada.ca)<br>Central bank focused on maintaining low, stable inflation and promoting economic and financial welfare for Canada's overall economic health. | Banking | 🇨🇦 Ottawa | 2,496 | 1935 |
| 12 | [VON Canada](https://www.tamtam.ai/c/von-canada) (von.ca)<br>A nonprofit organization providing innovative clinical, personal, and social support services for people to live comfortably in their own homes | Home Health Care Services | 🇨🇦 Ottawa | 1,879 | 1897 |
| 13 | [Queensway Carleton Hospital](https://www.tamtam.ai/c/queensway-carleton-hospital) (qch.on.ca)<br>A patient and family-centered hospital in Ottawa providing acute care services with a focus on emergency, childbirth, geriatrics, mental health, and rehabilitation | Hospitals and Health Care | 🇨🇦 Ottawa | 1,335 | 1976 |
| 14 | [Bruyère Health](https://www.tamtam.ai/c/bruyere-health) (bruyere.org)<br>The company provides a range of health care services including rehabilitation, complex care, family health teams, long-term care, and senior living options Their mission is to enhance quality of life through integrated care | Hospitals and Health Care | 🇨🇦 Ottawa | 1,298 | 1845 |
| 15 | [CATSA / ACSTA](https://www.tamtam.ai/c/catsa-acsta) (catsa-acsta.gc.ca)<br>A government corporation in Canada responsible for air transportation security, including screening passengers, baggage, and airport workers at major airports nationwide | Airlines and Aviation | 🇨🇦 Ottawa | 1,184 | 2002 |
| 16 | [University of Ottawa Heart Institute](https://www.tamtam.ai/c/university-of-ottawa-heart-institute) (ottawaheart.ca)<br>A leading cardiovascular health center in Canada providing high-tech, personalized care, advancing cardiac medicine through research, and pioneering new treatments globally | Hospitals and Health Care | 🇨🇦 Ottawa | 1,087 |  |
| 17 | [Hôpital Montfort](https://www.tamtam.ai/c/hopital-montfort) (hopitalmontfort.com)<br>An academic hospital in Ontario, focused on exceptional patient care and staff well-being, emphasizing collaboration, innovation, and skill development | Hospitals and Health Care | 🇨🇦 Ottawa | 1,054 | 1953 |
| 18 | [The Royal](https://www.tamtam.ai/c/the-royal) (theroyal.ca)<br>specialized mental health care, advocacy, research, education, and fundraising to support recovery for complex and treatment-resistant mental illness | Hospitals and Health Care | 🇨🇦 Ottawa | 962 | 1910 |
| 19 | [Ottawa Police Service](https://www.tamtam.ai/c/ottawa-police-service) (ottawapolice.ca)<br>A dedicated police service in Ottawa providing excellent service since 1995 Connect with us online for career opportunities and recruitment information | Law Enforcement | 🇨🇦 Ottawa | 834 | 1995 |
| 20 | [Canadian North](https://www.tamtam.ai/c/canadian-north) (canadiannorth.com)<br>A transportation service provider connecting people and communities in Inuit Nunangat and NWT through cargo, charter, and scheduled flights | Airlines and Aviation | 🇨🇦 Ottawa | 827 |  |
| 21 | [Alterna Savings](https://www.tamtam.ai/c/alterna-savings) (alterna.ca)<br>A leading financial institution with over 115 years of experience, offering a wide range of services to over 200,000 members across Ontario | Financial Services | 🇨🇦 Ottawa | 656 | 1908 |
| 22 | [OC Transpo](https://www.tamtam.ai/c/oc-transpo) (octranspo.com)<br>Public transportation provider in Canada's national capital with a fleet of accessible buses and trains, focused on sustainability and expanding light rail system | Urban Transit Services | 🇨🇦 Ottawa | 553 | 1973 |
| 23 | [Carefor Health & Community Services](https://www.tamtam.ai/c/carefor-health-and-community-services) (carefor.ca)<br>Providing home health care and community support services since 1897, supporting seniors and people with disabilities to live with choice and dignity in Eastern Ontario | Hospitals and Health Care | 🇨🇦 Ottawa | 464 | 1897 |
| 24 | [Payments Canada](https://www.tamtam.ai/c/payments-canada) (payments.ca)<br>Facilitating billions of dollars in daily transactions, this organization supports Canada's economy through essential clearing and settlement infrastructure for payments | Banking | 🇨🇦 Ottawa | 435 | 1980 |
| 25 | [Ottawa Public Health - Santé publique Ottawa](https://www.tamtam.ai/c/ottawa-public-health-sante-publique-ottawa) (ottawapublichealth.ca)<br>A public health organization in Ottawa working with community partners to improve residents' health and safety through programs, services, and public policies | Wellness and Fitness Services | 🇨🇦 Ottawa | 400 | 1969 |
| 26 | [EORLA - Eastern Ontario Regional Laboratory Association](https://www.tamtam.ai/c/eorla-eastern-ontario-regional-laboratory-association) (eorla.ca)<br>A non-profit organization operating 19 hospital-based clinical laboratories in Eastern Ontario, providing high-quality, patient-focused diagnostic testing services to the region | Hospitals and Health Care | 🇨🇦 Ottawa | 364 | 2012 |
| 27 | [Home and Community Care Support Services Champlain](https://www.tamtam.ai/c/home-and-community-care-support-services-champlain) (healthcareathome.ca)<br>Providing exceptional care to individuals in their homes, with a commitment to quality and compassion | Hospitals and Health Care | 🇨🇦 Ottawa | 263 |  |
| 28 | [First Air](https://www.tamtam.ai/c/first-air) (canadiannorth.com)<br>A leading airline in Canada's Arctic, providing scheduled passenger and cargo services to over 30 northern communities with a fleet of 17 aircraft | Airlines and Aviation | 🇨🇦 Ottawa | 236 | 1946 |
| 29 | [Telesat](https://www.tamtam.ai/c/telesat) (telesat.com)<br>Provides satellite communication services, headquartered in Ottawa with offices in the United States and Brazil, acquired by Loral Space & Communications and Public Pension Investment Board. | Telecommunications | 🇨🇦 Ottawa | 201 | 1969 |
| 30 | [Energy Ottawa](https://www.tamtam.ai/c/energy-ottawa) (energyottawa.com)<br>Innovative energy company in Ontario producing green power through hydroelectric, solar, and landfill gas-to-energy facilities, along with energy management and infrastructure services | Utilities | 🇨🇦 Ottawa | 11 |  |

## How this list is built

Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.

## More company lists in Ottawa

- [The largest companies in Ottawa](https://www.tamtam.ai/l/largest-companies-ottawa) (350)
- [Public sector organisations in Ottawa](https://www.tamtam.ai/l/public-sector-organisations-ottawa) (49)
- [Multinational companies in Ottawa](https://www.tamtam.ai/l/multinational-companies-ottawa) (42)
- [Education providers in Ottawa](https://www.tamtam.ai/l/education-companies-ottawa) (30)
- [Government Administration companies in Ottawa](https://www.tamtam.ai/l/government-administration-companies-ottawa) (30)

## The same list elsewhere in Canada

- [Critical infrastructure operators in Canada](https://www.tamtam.ai/l/critical-infrastructure-operators-canada) (767)
- [Critical infrastructure operators in Ontario](https://www.tamtam.ai/l/critical-infrastructure-operators-ontario) (344)
- [Critical infrastructure operators in the province of Quebec](https://www.tamtam.ai/l/critical-infrastructure-operators-province-of-quebec) (126)
- [Critical infrastructure operators in Alberta](https://www.tamtam.ai/l/critical-infrastructure-operators-alberta) (124)
- [Critical infrastructure operators in British Columbia](https://www.tamtam.ai/l/critical-infrastructure-operators-british-columbia) (78)
- [Critical infrastructure operators in Manitoba](https://www.tamtam.ai/l/critical-infrastructure-operators-manitoba) (27)
- [Critical infrastructure operators in Toronto](https://www.tamtam.ai/l/critical-infrastructure-operators-toronto) (120)
- [Critical infrastructure operators in Calgary](https://www.tamtam.ai/l/critical-infrastructure-operators-calgary) (83)
- [Critical infrastructure operators in Montreal](https://www.tamtam.ai/l/critical-infrastructure-operators-montreal) (51)
- [Critical infrastructure operators in Vancouver](https://www.tamtam.ai/l/critical-infrastructure-operators-vancouver) (26)
- [Critical infrastructure operators in Mississauga](https://www.tamtam.ai/l/critical-infrastructure-operators-mississauga) (24)

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Source: https://www.tamtam.ai/l/critical-infrastructure-operators-ottawa