| # | Company | Employees |
|---|---|---|
| 1 |
Canada Post / Postes Canadacanadapost-postescanada.ca
Nationwide postal service with extensive retail network, delivering parcels and mail to over 17 million Canadian addresses. |
23,941 |
| 2 |
Canadian Armed Forces | Forces armées canadiennesforces.ca
Offering over 100 trades, the organization provides world-class qualifications, competitive salaries, benefits, stability, and exciting opportunities for travel, adventure, and making a difference |
20,412 |
| 3 |
CBC/Radio-Canadacbc.radio-canada.ca
Canadian public broadcaster promoting Canadian culture through diverse programming in multiple languages, supporting creative work and job opportunities in television production |
14,336 |
| 4 |
City of Ottawa / Ville d’Ottawajobs-emplois.ottawa.ca
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 |
9,194 |
| 5 |
Health Canada | Santé Canadahealth.canada.ca
A Federal department in Canada focused on improving health for individuals through recruitment of professionals in various fields and student programs |
8,686 |
| 6 |
The Ottawa Hospitalottawahospital.on.ca
Innovative teaching and research hospital providing specialized care, developing new treatments, and improving patient care through community engagement and global impact |
7,679 |
| 7 |
Carleton Universitycarleton.ca
University located near government and high tech companies, combining research and teaching to provide superior education and solve real problems. |
6,886 |
| 8 |
Ottawa-Carleton District School Board (OCDSB)ocdsb.ca
A large school board in Eastern Ontario offering a wide range of programs to support students in academics, arts, athletics, and technology |
6,863 |
| 9 |
Agriculture and Agri-Food Canada/ Agriculture et Agroalimentaire Canadaagriculture.canada.ca
Agriculture and agri-food company supporting farmers and food producers in growth and development Terms of use: http://owly/gnCW50FjUsI / http://owly/XHSU50FjUvL |
6,405 |
| 10 |
Statistics Canada | Statistique Canadastatcan.gc.ca
A leading statistical agency providing relevant, accurate, and timely data to help Canadians better understand their country through an app and podcast series |
5,917 |
| 11 |
Fisheries and Oceans Canada / Pêches et Océans Canadadfo-mpo.gc.ca
Manage fisheries and aquaculture sustainably, protect aquatic ecosystems, maintain navigable waterways, and respond to maritime emergencies with Indigenous collaboration. |
5,665 |
| 12 |
Correctional Service Canada │ Service correctionnel Canadacsc-scc.gc.ca
Administer federal prison sentences, manage institutions with various security levels, and supervise offenders under conditional release in communities. |
5,587 |
| 13 |
Transport Canada - Transports Canadatc.canada.ca
A department with 5000 employees nationwide seeks individuals to contribute to meaningful work, growth opportunities, attractive benefits, and inclusive work environment |
5,540 |
| 14 |
Shared Services Canada | Services partagés Canadacanada.ca
Modernizing Government of Canada's IT infrastructure by delivering email, data centre, telecommunication, videoconferencing, and Wi-Fi services to customers |
5,161 |
| 15 |
Algonquin College of Applied Arts and Technologyalgonquincollege.com
Leading college in eastern Ontario offering diverse hands-on learning programs, including degrees, diplomas, and certificates, with a strong focus on student success and innovation |
4,972 |
| 16 |
Ottawa Catholic School Boardocsb.ca
Providing faith-based, inclusive education with English and French programs, fostering critical thinking, creativity, well-being, and community connections. |
4,559 |
| 17 |
Canada Border Services Agency | Agence des services frontaliers du Canadacbsa-asfc.gc.ca
Ensures national security and economic prosperity by managing and monitoring international travel and trade at Canada's borders. |
4,369 |
| 18 |
Canadian Food Inspection Agencyinspection.canada.ca
A federal regulator in Canada focused on enhancing food safety, animal health, and protecting plant resources with a commitment to employee growth and impact |
4,024 |
| 19 |
Canadian Blood Servicesblood.ca
Canada's national organization responsible for ensuring a secure and sustainable supply of blood and organs for transfusion and transplantation |
3,745 |
| 20 |
Canadian Coast Guard/Garde côtière canadiennecanada.ca
A federal agency that operates a civilian fleet and provides maritime services to Canadians, ensuring safe waters, environmental protection, and economic growth |
2,892 |
| 21 |
Canada Mortgage and Housing Corporation (CMHC) Société canadienne d'hypothèques et de logement(SCHL)cmhc-schl.gc.ca
Provide housing financing solutions, implement government housing programs, and share research and data to support the housing sector. |
2,887 |
| 22 |
CHEOcheo.on.ca
A global leader in pediatric health care and research, providing excellence in complex care, education, and community partnership for children and youth |
2,784 |
| 23 |
Export Development Canada | Exportation et développement Canadalinktr.ee
Provide financial products, trade knowledge, and support to Canadian businesses for global growth, risk management, and sustainable inclusive trade. |
2,752 |
| 24 |
Bank of Canadabankofcanada.ca
Central bank focused on maintaining low, stable inflation and promoting economic and financial welfare for Canada's overall economic health. |
2,496 |
| 25 |
Collège La Citécollegelacite.ca
Discover life in the largest French-speaking college in Ontario Stay informed about job opportunities Dynamic, inclusive environment with top employer rankings Follow on social media for more |
2,069 |
| 26 |
Conseil des écoles publiques de l'Est de l'Ontario (CEPEO)cepeo.on.ca
A leading public school board in Eastern Ontario offering diverse and inclusive educational opportunities for students and employees to thrive |
1,604 |
| 27 |
Canadian Forces Morale and Welfare Servicescfmws.ca
The company supports Canadian Armed Forces members and their families worldwide with fitness, recreation, family support, retail, and financial services |
1,407 |
| 28 |
Defence Construction Canadadcc-cdc.gc.ca
A Crown corporation providing contracting, construction management, infrastructure, environmental, and lifecycle support services for Canada's defence requirements through five service lines |
1,372 |
| 29 |
Queensway Carleton Hospitalqch.on.ca
A patient and family-centered hospital in Ottawa providing acute care services with a focus on emergency, childbirth, geriatrics, mental health, and rehabilitation |
1,335 |
| 30 |
CATSA / ACSTAcatsa-acsta.gc.ca
A government corporation in Canada responsible for air transportation security, including screening passengers, baggage, and airport workers at major airports nationwide |
1,184 |
| 31 |
University of Ottawa Heart Instituteottawaheart.ca
A leading cardiovascular health center in Canada providing high-tech, personalized care, advancing cardiac medicine through research, and pioneering new treatments globally |
1,087 |
| 32 |
Hôpital Montforthopitalmontfort.com
An academic hospital in Ontario, focused on exceptional patient care and staff well-being, emphasizing collaboration, innovation, and skill development |
1,054 |
| 33 |
The Royaltheroyal.ca
specialized mental health care, advocacy, research, education, and fundraising to support recovery for complex and treatment-resistant mental illness |
962 |
| 34 |
Canadian Nuclear Safety Commission – Commission canadienne de sûreté nucléairenuclearsafety.gc.ca
Regulating nuclear energy use and materials to protect health, safety, security, and the environment, while disseminating objective scientific and technical information to the public |
958 |
| 35 |
Royal Canadian Mintmint.ca
The company is a for-profit Crown Corporation responsible for producing coins, managing coinage systems, providing advice on coinage matters, and marketing bullion products |
876 |
| 36 |
Ottawa Police Serviceottawapolice.ca
A dedicated police service in Ottawa providing excellent service since 1995 Connect with us online for career opportunities and recruitment information |
834 |
| 37 |
Natural Sciences and Engineering Research Council of Canada (NSERC)nserc-crsng.gc.ca
Investments in natural sciences and engineering research, supporting discoveries, industry partnerships, and training for over 30,000 students and fellows. |
673 |
| 38 |
International Development Research Centre (IDRC)idrc-crdi.ca
A champion in funding research and innovation in developing regions to drive global change, promote sustainability, and inclusivity through knowledge sharing |
633 |
| 39 |
Canadian Army | Armée canadiennecanada.ca
The Canadian Army is the land component of the Canadian Armed Forces, producing well-trained soldiers ready for operations at home and abroad |
565 |
| 40 |
OC Transpooctranspo.com
Public transportation provider in Canada's national capital with a fleet of accessible buses and trains, focused on sustainability and expanding light rail system |
553 |
| 41 |
National Gallery of Canadagallery.ca
Preserving and showcasing a diverse collection of over 75,000 works of art from various artistic traditions, including Canadian and Indigenous art |
288 |
| 42 |
Energy Ottawaenergyottawa.com
Innovative energy company in Ontario producing green power through hydroelectric, solar, and landfill gas-to-energy facilities, along with energy management and infrastructure services |
11 |
Turn this list into pipeline
Tamtam finds the decision-makers at every company on a list like this one, with verified emails, phone numbers and the buying signals that tell you when to reach out.
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 Oct 24, 2026.
More company lists in Ottawa
The same list elsewhere in Canada
- Public sector organisations in Canada 499
- Public sector organisations in Ontario 196
- Public sector organisations in the province of Quebec 130
- Public sector organisations in British Columbia 59
- Public sector organisations in Alberta 52
- Public sector organisations in Toronto 43
- Public sector organisations in Montreal 41
- Public sector organisations in Quebec City 31