# Consulting firms headquartered in Montreal

Tamtam tracks 52 consulting firms headquartered in Montreal. This list ranks the 30 largest by number of employees on LinkedIn, led by SNC-Lavalin, WSP in Canada and Logica. Their median headcount is 559. Half of them were founded in 1992 or later.

This selection of large consulting firms in Montreal focuses on professional services, IT consulting, and engineering. Among them are SNC-Lavalin, a global engineering services and nuclear organization, and WSP in Canada, a professional services firm with expertise in engineering, advisory, and science. BDC supports entrepreneurs through financing and consulting, while Raymond Chabot Grant Thornton offers assurance, taxation, and consulting services. Alithya provides digital technology services, and BPA specializes in mechanical, electrical, and structural engineering.

A notable pattern among these companies is their significant employee count, indicating a concentration of large-scale operations within Montreal's consulting sector. All the companies listed have their headquarters in Montreal, highlighting the city as a central hub for these professional and engineering services.

🇨🇦 Montreal · 30 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [SNC-Lavalin](https://www.tamtam.ai/c/snc-lavalin) (atkinsrealis.com)<br>Global engineering services and nuclear organization connecting people, data, and technology to transform infrastructure and energy systems worldwide. | Civil Engineering | 🇨🇦 Montreal | 11,913 |  |
| 2 | [WSP in Canada](https://www.tamtam.ai/c/wsp-in-canada) (wsp.com)<br>professional services firm unites engineering, advisory, science expertise; shapes communities; advances humanity; delivers projects across sectors globally. | Professional Services | 🇨🇦 Montreal | 10,459 | 1959 |
| 3 | [Logica](https://www.tamtam.ai/c/logica) (cgi.com)<br>Global provider of IT and business process services, offering consulting, integration, and outsourcing with a team of 69,000 professionals across 40 countries | IT Services and IT Consulting | 🇨🇦 Montreal | 6,113 |  |
| 4 | [BDC](https://www.tamtam.ai/c/bdc) (bdc.ca)<br>A leading Canadian bank focused on supporting entrepreneurs through financing, consulting, and specialized financing services for small and medium-sized enterprises | Banking | 🇨🇦 Montreal | 4,739 | 1944 |
| 5 | [Raymond Chabot Grant Thornton](https://www.tamtam.ai/c/raymond-chabot-grant-thornton) (rcgt.com)<br>A leading accounting firm with over 2,300 professionals offering assurance, taxation, consulting, and business recovery services in Quebec and globally | Professional Services | 🇨🇦 Montreal | 2,426 | 1948 |
| 6 | [Alithya](https://www.tamtam.ai/c/alithya) (alithya.com)<br>A global digital technology services company providing practical IT solutions tailored to complex business challenges, with a focus on strategy and digital transformation | IT Services and IT Consulting | 🇨🇦 Montreal | 2,418 |  |
| 7 | [BPA](https://www.tamtam.ai/c/bpa-montreal) (bpa.ca)<br>An engineering firm specializing in mechanical, electrical, structural engineering, building science, and more for commercial, institutional, and industrial markets across Canada | Engineering Services | 🇨🇦 Montreal | 1,269 | 1956 |
| 8 | [COFOMO](https://www.tamtam.ai/c/cofomo) (cofomo.com)<br>Canadian IT and business consulting leader specializing in digital transformation with a team of 3,000 professionals offering innovative solutions nationwide | Business Consulting and Services | 🇨🇦 Montreal | 1,201 | 1995 |
| 9 | [AVENIR GLOBAL](https://www.tamtam.ai/c/avenir-global) (avenir.global)<br>A global holding and management group with specialized communication agencies in Canada, the US, Europe, and the Middle East | Public Relations and Communications Services | 🇨🇦 Montreal | 1,020 | 1976 |
| 10 | [Richter](https://www.tamtam.ai/c/richter) (richter.ca)<br>Business \| Family Office providing strategic advice on business and family matters, guiding successful entrepreneurs to shape their legacy across generations | Professional Services | 🇨🇦 Montreal | 922 | 1926 |
| 11 | [Stantec au Québec](https://www.tamtam.ai/c/stantec-au-quebec) (stantec.com)<br>Global leader in engineering and sustainable development, with expertise in various sectors, providing services from concept to completion with innovation and client needs in mind | Business Consulting and Services | 🇨🇦 Montreal | 801 | 1954 |
| 12 | [SNC-Lavalin Rail & Transit (formerly Interfleet)](https://www.tamtam.ai/c/snc-lavalin-rail-and-transit-formerly-interfleet) (snclavalin.com)<br>Global engineering and construction group providing industry-leading services in infrastructure, oil and gas, mining, power, and rail and transit systems | Truck Transportation | 🇨🇦 Montreal | 659 | 1911 |
| 13 | [Artelia Canada](https://www.tamtam.ai/c/artelia-canada) (arteliagroup.ca)<br>Multidisciplinary engineering firm providing innovative solutions in mobility, energy, environment, water, industry, and telecom across Canada with global expertise. | Engineering Services | 🇨🇦 Montreal | 642 |  |
| 14 | [gbi](https://www.tamtam.ai/c/gbi) (gbi.ca)<br>With over 60 years of experience, we specialize in innovative and sustainable engineering solutions for various sectors, including residential, education, healthcare, and infrastructure | Engineering Services | 🇨🇦 Montreal | 614 | 1963 |
| 15 | [Optimum Financial Group](https://www.tamtam.ai/c/optimum-financial-group) (optimumfinancier.com)<br>Financial group providing services in actuarial consulting, asset management, insurance, IT, and real estate Operating globally with over 600 employees and significant assets under management | Financial Services | 🇨🇦 Montreal | 559 | 1969 |
| 16 | [LAPORTE](https://www.tamtam.ai/c/laporte) (laporteconsultants.com)<br>Specialized engineering firm providing process, building, and utility design solutions to Pharmaceutical, Agrifood, and Bioindustrial industries globally with long-term client relationships | Engineering Services | 🇨🇦 Montreal | 543 | 1999 |
| 17 | [Groupe ABS](https://www.tamtam.ai/c/groupe-abs) (groupeabs.com)<br>Established in 1993, Groupe ABS offers a wide range of services in material engineering, geotechnics, environmental science, and specialized divisions in drilling and contaminated soil treatment | Civil Engineering | 🇨🇦 Montreal | 492 | 1993 |
| 18 | [Tetra Tech au Québec](https://www.tamtam.ai/c/tetra-tech-au-quebec) (tetratech.com)<br>A global leader in consulting, engineering, and technical services with expertise in various sectors, providing innovative solutions for projects worldwide | Civil Engineering | 🇨🇦 Montreal | 485 |  |
| 19 | [GCM Consultants](https://www.tamtam.ai/c/gcm-consultants) (gcmconsultants.com)<br>The company delivers high-performance engineering services for various industrial sectors, offering studies, engineering, project management, and construction services for projects up to $200M | Business Consulting and Services | 🇨🇦 Montreal | 432 |  |
| 20 | [Beyond Technologies](https://www.tamtam.ai/c/beyond-technologies) (beyondtechnologies.com)<br>Professional services specializing in SAP integration and business process optimization, leveraging extensive industry expertise to deliver practical, innovative solutions. | IT Services and IT Consulting | 🇨🇦 Montreal | 414 | 2005 |
| 21 | [Normandin Beaudry](https://www.tamtam.ai/c/normandin-beaudry) (normandin-beaudry.ca)<br>Established in 1992, this consulting firm in Montreal, Toronto, and Quebec City specializes in human capital and financial performance through advisory services in eight areas of expertise | Human Resources Services | 🇨🇦 Montreal | 401 | 1992 |
| 22 | [MSP Corp](https://www.tamtam.ai/c/msp-corp) (mspcorp.ca)<br>This company acquires and empowers high-performing Managed Service Providers in North America, providing resources, technology, and business support to enhance their services | IT Services and IT Consulting | 🇨🇦 Montreal | 398 | 2020 |
| 23 | [Mecanica](https://www.tamtam.ai/c/mecanica) (mecanicasolutions.com)<br>Global provider of engineering services for aerospace, automotive, and AEC industries Specializing in PLM/CAD/CAM solutions, onsite support, R&D, engineering services, and custom software development for clients | Engineering Services | 🇨🇦 Montreal | 393 | 1983 |
| 24 | [Therrien Couture Joli-Coeur](https://www.tamtam.ai/c/therrien-couture-joli-coeur) (groupetcj.ca)<br>A multidisciplinary team supports clients and partners with a collaborative, innovative, and value-creating approach, focusing on commitment, audacity, simplicity, and relevance | Law Practice | 🇨🇦 Montreal | 338 | 1994 |
| 25 | [ATELKA](https://www.tamtam.ai/c/atelka) (ttec.com)<br>Global customer experience provider offering omnichannel solutions through consulting, technology services, and customer care operations to enhance client relationships and interactions | Outsourcing and Offshoring Consulting | 🇨🇦 Montreal | 319 | 2003 |
| 26 | [ALTEN Canada](https://www.tamtam.ai/c/alten-canada) (alten.ca)<br>Global consulting firm specializing in Engineering and IT, with over 30 years experience Providing specialized professionals, tailored solutions, and employee-focused support | IT Services and IT Consulting | 🇨🇦 Montreal | 318 | 2012 |
| 27 | [Tetra Tech Industries](https://www.tamtam.ai/c/tetra-tech-industries) (tetratech.com)<br>A global provider of advanced engineering services for heavy industries, specializing in plant engineering, investment program management, and construction projects | Mechanical Or Industrial Engineering | 🇨🇦 Montreal | 255 |  |
| 28 | [Victrix](https://www.tamtam.ai/c/victrix) (victrix.ca)<br>A leading IT services company in Quebec, specializing in implementing enterprise productivity solutions to enhance performance and competitiveness through specialized technology services | IT Services and IT Consulting | 🇨🇦 Montreal | 240 | 2003 |
| 29 | [Tink](https://www.tamtam.ai/c/tink-montreal) (tink.ca)<br>A leading digital agency in Montreal offering a wide range of services including development, strategy, marketing, design, hosting, and 24/7 support | IT Services and IT Consulting | 🇨🇦 Montreal | 233 | 1995 |
| 30 | [LIDD Supply Chain Consultants](https://www.tamtam.ai/c/lidd-supply-chain-consultants) (lidd.com)<br>Global consulting firm specializing in supply chain strategy, technology, and infrastructure for consumer products, food & beverage, retail, e-commerce, and distribution industries | Business Consulting and Services | 🇨🇦 Montreal | 182 | 2009 |

## 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 12, 2026.

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## The same list elsewhere in Canada

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- [Consulting firms in Vancouver](https://www.tamtam.ai/l/consulting-firms-vancouver) (28)

## The same list elsewhere

- [Consulting firms in the world](https://www.tamtam.ai/l/consulting-firms-in-the-world) (16,009)

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Source: https://www.tamtam.ai/l/consulting-firms-montreal