This list features a selection of electronics and semiconductor companies based in Ontario. The companies range from large global players like Celestica, which offers design and manufacturing solutions across various high-tech sectors, to mid-sized firms such as Canadian Solar Inc., a global manufacturer of photovoltaic modules. Other notable companies include Huawei Canada, a telecommunications provider, and Tenstorrent, which builds AI computers.
A common pattern among these companies is their strong presence in advanced technology sectors. While Toronto is a prominent headquarters city, there is also a significant cluster of companies in the Kitchener-Waterloo area, such as Teledyne DALSA, specializing in image sensing, and Thalmic Labs, focused on wearable technology.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Celesticacelestica.com
Global leader in providing design, manufacturing, and supply chain solutions for aerospace, defense, communications, healthtech, and more, delivering innovative solutions for complex challenges |
16,022 | |||
| 2 |
Canadian Solar Inc.csisolar.com
Global manufacturer of photovoltaic modules and inverters developing utility-scale solar power and battery energy storage projects with over 165 GW delivered worldwide. |
2,240 | |||
| 3 |
Huawei Canadaconsumer.huawei.com
A global provider of ICT infrastructure and smart devices, committed to connecting the world through innovative research and development in Canada |
1,758 | |||
| 4 |
Tenstorrenttenstorrent.com
Tenstorrent builds next-generation AI computers, combining expertise in computer architecture, ASIC design, systems, and neural network compilers Offices worldwide Join our team! |
1,226 | |||
| 5 |
Teledyne DALSAteledynedalsa.com
Specialized in high-performance image sensing, semiconductor fabrication, and 3D geospatial systems with global R&D and support locations. |
863 | |||
| 6 |
Alphawave Semiawavesemi.com
Specializing in silicon technology for digital communication networks, we strive to provide high performance, reliability, and low power solutions |
702 | |||
| 7 |
Silfab Solar Inc.silfabsolar.com
North American designer and manufacturer of high-efficiency photovoltaic modules using automated production lines across facilities in Washington, Toronto, and South Carolina. |
421 | |||
| 8 | 348 | ||||
| 9 |
Thalmic Labsthalmic.com
Pioneering wearable technology company revolutionizing human-device interaction with the Myo armband, measuring muscle activity to control digital devices wirelessly |
334 | |||
| 10 |
Panasonic Canadapanasonic.com
A provider of digital and electronics products and solutions for consumer, business, and industrial needs, empowering professionals and improving lives with innovative technologies |
294 | |||
| 11 |
GAO RFID Inc.gaorfid.com
A leading supplier of RFID products and solutions, offering high-quality off-the-shelf products and customized solutions to a global customer base |
233 | |||
| 12 |
NDI (Northern Digital Inc.)ndigital.com
Global leader in optical and electromagnetic navigation technology for medical devices, offering accurate instrument tracking in various applications for improved workflow and procedure efficacy |
229 | |||
| 13 |
Amphenol Canada Corp.amphenolcanada.com
Global provider of interconnect solutions for electronic equipment manufacturers worldwide across various industries, with a focus on design creativity, cost effectiveness, and leading-edge technology |
206 | |||
| 14 |
Gastopsgastops.com
Specializing in advanced equipment health sensing and analysis products, engineering services, and proactive maintenance solutions for defense, aerospace, energy, and marine industries |
191 | |||
| 15 |
ECI Technology Group Inc.ecitech.com
Full turnkey electronics manufacturing service provider specializing in Electro-Mechanical design, development, and manufacturing solutions for a wide range of electronics OEMs |
135 | |||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 16 |
KATEK Canadakontron.com
An Electronic Manufacturing Services provider specializing in end-to-end assembly services for complex electronic products in various industries, focused on innovation and operational excellence |
131 | |||
| 17 |
Microart Services Inc.microartservices.com
Electronic manufacturing and design services company offering circuit design, PCB layout, manufacturing, assembly, testing, and box build for prototype and low-to-mid volume productions |
125 | |||
| 18 |
OES Inc.oes-inc.com
The company specializes in providing EMS solutions, LED video displays, scoreboard solutions, and wire harness quality assurance devices for various industries worldwide |
125 | |||
| 19 |
TDG Transit Design Group Inctdgdesign.com
An industry leader in developing LED, Fluorescent, and energy storage solutions for rail vehicles with a global presence since 1989 Specializing in innovative lighting systems |
118 | |||
| 20 |
Jabil Software Servicesjabil.com
A global manufacturing solutions provider focused on technological advancement, trusted by leading brands, with a commitment to positive impact and employee growth |
111 | |||
| 21 |
Safran Electronics & Defense Canada Inc.safran-group.com
Specializing in aerospace and defense applications, the company develops, produces, and maintains embedded computers and systems with full engineering and support capabilities |
77 | |||
| 22 |
MIS Electronics Inc.miselectronics.com
Electronic manufacturing services company serving industries such as defense, medical, aerospace, and more; focusing on quality, speed, and cost-effectiveness for customer success |
43 | |||
| 23 |
LightMachinerylightmachinery.com
Specializing in high-quality lasers, optical components, and process machinery, the company produces tight tolerance components and cutting-edge equipment |
41 | |||
| 24 |
RMF Design and Manufacturing Inc.rmfdesign.com
Provider of electronic design and manufacturing services for clients in Canada and the United States Specializing in engineering, programming, prototyping, and turnkey manufacturing |
36 | |||
| 25 | 36 | ||||
| 26 |
STIM Canada Inc.stimcanada.com
A well-established Electronics Manufacturing Services company partnering with top OEMs, offering flexible solutions and solid partnerships since 1982 |
21 | |||
| 27 |
BMV Optical Technologies Inc.bmvoptical.com
Experienced manufacturer of custom optical components and systems with capabilities from raw material to final product, offering rapid turnaround and high-quality solutions |
14 | |||
| 28 |
Circuit Centre Inccircuitcentre.com
Advanced electronics design, manufacturing, and test services company with a focus on long-term client relationships, quality excellence, and cutting-edge technology |
10 | |||
| 29 |
Universal Quantum Devices Inc. (UQDevices)uqdevices.com
Specializing in quantum technologies, this company based in Waterloo, Ontario offers solutions for quantum cryptography, photon correlation experiments, and real-world applications in space |
3 | |||
| 30 |
Eci Technology Group Incecitech.com
An electronic manufacturing solution provider offering design, assembly, testing, and full box build services with a focus on trust, integrity, and quality performance |
3 | |||
| 31 |
Mektronix Systems Corp
An electrical/electronic manufacturing company specializing in product development and design for various industries |
2 | |||
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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.
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