Cornwall, ON

Find the Best Contractors in Cornwall

Discover top-rated home service professionals in Cornwall, Ontario. Browse 198 verified contractors for roofing, HVAC, plumbing, and more.

198

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4.5

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Cornwall, ON

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Top Contractors in Cornwall, ON

Showing 1-20 of 198 contractors

Blair Martell Excavation & Landscaping

Blair Martell Excavation & Landscaping

624 Yolanda St, Cornwall, ON K6K 1P2

5(2 reviews)
LandscapingDemolition
Hours
Opsun Operation Center

Opsun Operation Center

3318 Second St E, Cornwall, ON K6H 6J8

5(2 reviews)

"Fast offloading Receiving 8am-4pm Overnight parking"

Solar
Hours
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The Water Heater Guy

The Water Heater Guy

1400 Dover Rd, Cornwall, ON K6J 1V5

5(2 reviews)

"Great and quick service highly recommended"

Plumbing
Hours
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Astro Electric Industrial Maintenance

Astro Electric Industrial Maintenance

122 St Felix St, Cornwall, ON K6H 5A3

5(1 reviews)
Electrical
Hours
Cotnam Plumbing Inc.

Cotnam Plumbing Inc.

17508 Headline Rd, Long Sault, ON K6H 7V4

5(8 reviews)

"Knowledgeable and great fast service!!"

PlumbingBathroom Remodel
Hours
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Prestige Brick & Stone Incorporated

Prestige Brick & Stone Incorporated

1420 Boundary Rd, Cornwall, ON K6H 7P8

5(19 reviews)

"Good pricing, quick delivery, fast response time."

LandscapingConcreteGeneral ContractingDrywall+2 more
Hours
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quality-heating

quality-heating

Cornwall, ON

5(1 reviews)

"Fast and professional service."

HVAC
Hours
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E W Pryer Plumbing Ltd

E W Pryer Plumbing Ltd

5701 Richmond Dr, Long Sault, ON K0C 1P0

5(17 reviews)

"Great plumber quick and knows his stuff."

Plumbing
Hours
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EverFlow Plumbing Inc

EverFlow Plumbing Inc

Cornwall, ON

5(5 reviews)

"They are courteous, professional and knowledgeable and extremely responsive."

Plumbing
Hours
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MJV Electrical

MJV Electrical

161 Marguerite D'youville St, Cornwall, ON K6H 7K2

5(8 reviews)

"I felt like he was honest and worked fast to resolve the problem ."

ElectricalDecks & Patios
Hours
Oscar Ladouceur & Son Ltd

Oscar Ladouceur & Son Ltd

235 Saunders Dr, Cornwall, ON K6H 5R6

5(3 reviews)
HVACPlumbingGeneral ContractingMasonry
Hours
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Stang Electric Inc

Stang Electric Inc

Cornwall, ON

5(20 reviews)

"They explained the job so I understood what they needed to do."

Electrical
Hours
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Trans-Canada Wire & Cable Co

Trans-Canada Wire & Cable Co

812 Pitt St, Cornwall, ON K6J 5R6

5(1 reviews)
Electrical
Hours
P.B. Electric ltd

P.B. Electric ltd

17349 Cornwall Centre Rd, Cornwall, ON K6K 1K6

5(5 reviews)

"Electric ltd for your quick response, giving me peace of mind."

Electrical
Hours
Laframboise Mechanical-Electrical

Laframboise Mechanical-Electrical

40 William St, Cornwall, ON K6H 1H7

5(1 reviews)
Electrical
Hours
Doug Gordon Refrigeration

Doug Gordon Refrigeration

880 Tenth St E, Cornwall, ON K6H 5T1

5(3 reviews)

"Professional and extremely reliable service!"

HVAC
Hours
Bellatin HVAC

Bellatin HVAC

Cornwall, ON

5(6 reviews)

"Very responsive, knowledgeable and fair."

HVAC
Hours
Image Renovations Cornwall

Image Renovations Cornwall

Cornwall, ON

5(8 reviews)

"He got back to me within a few days and his price matched my budget."

PlumbingElectricalKitchen RemodelBathroom Remodel+8 more
Hours
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Mike Paquette Mechanical

Mike Paquette Mechanical

6550 Sapphire Dr, Cornwall, ON K6H 7J1

5(4 reviews)

"A stand up guy, super honest!"

HVAC
Hours
The Water Heater Guy

The Water Heater Guy

6286 County Rd 27, Summerstown, ON K0C 2E0

5(120 reviews)

"Awesome quick service had water heater installed same day highly recommended"

HVACPlumbingFlooring
Hours
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Top Rated Contractors 2026

Cornwall, ON

Every contractor shown for Cornwall, Ontario is listed with the rating and review count from its public Google Business Profile, so you can compare local professionals on the same basis. Businesses marked as claimed have confirmed their own details, which is not the same as a licence or insurance check. Confirm licensing and insurance directly, then request at least three written estimates before you hire in Cornwall.

Frequently Asked Questions

Common questions about finding contractors in Cornwall

Prices in Cornwall depend on the trade, the size and complexity of the job, and the materials you choose. Small repairs often start in the low hundreds of dollars, while full replacements such as a roof, HVAC system, or kitchen can run from several thousand dollars upward. Request at least three written estimates for the same scope so you can compare local pricing fairly.

Start with the listings on this page, then confirm the licence directly with the licensing board that covers Ontario. Requirements vary by trade: some states license general contractors, while others license only electrical, plumbing, and HVAC work. Ask for the licence number and verify it yourself before signing anything.

Most listings in Cornwall are aggregated from public business data, including the Google Business Profile rating and review count shown on each page, and are not individually inspected by us. A listing marked as claimed simply means the owner has confirmed control of the business record; it is not a licence or insurance check. Always verify licensing, insurance, and references before you hire.

Costs in Ontario depend heavily on the trade and the project. Labour rates vary by region, licensed trades such as electrical and plumbing usually cost more per hour than general labour, and emergency or after-hours work carries a premium. Statewide averages are only a starting point; get itemized quotes from local contractors for your exact scope.

Permit rules are set by the local authority that covers Cornwall. Structural work, additions, and most electrical, plumbing, HVAC, and roofing replacements require a permit, while some cosmetic work does not. Ask who is pulling the permit and confirm it is issued in the correct name before work starts, because unpermitted work can complicate resale and insurance.

A deposit of roughly 10-30% of the contract price to cover materials is common in Cornwall, with the balance tied to milestones in a written contract. Be cautious of anyone demanding full payment up front, large cash-only payments, or payment before the work is scheduled. A written payment schedule protects both sides.

Compare quotes on the same written scope of work, not on the bottom line alone. Check that each quote lists materials and brands, labour, permits, cleanup, and exclusions, and ask how change orders are priced. A bid that is far below the others usually means something has been left out.

A contractor contract in Ontario should state the full scope, materials, total price and payment schedule, estimated start and completion dates, the licence number, how changes will be approved and priced, the warranty, and who handles permits and cleanup. Read it before signing and keep a copy.

Timelines in Cornwall vary widely by trade and scope, from a same-day repair to several months for a major remodel. Weather, permit queues, and material lead times all affect the schedule. Ask each contractor for a written timeline and confirm how they handle weather or inspection delays.

Read the Google review excerpts shown on each listing for patterns rather than judging only by the star average. Also check the state or provincial licensing board for complaints, ask the contractor for recent local references, and confirm they carry insurance. A single bad review matters less than a consistent theme.

Pricing in Cornwall reflects local labour rates, cost of living, demand, and how far crews have to travel. Dense metro areas and high-cost regions usually run above the state average, while smaller markets can be below it. The only accurate comparison is like-for-like quotes from contractors who work in Cornwall.

Document everything in writing first, including photos, dates, and the contract. Ask the contractor to fix the issue under the warranty, and if they refuse, file a complaint with the Ontario licensing board or consumer-protection office. You can also contact us so we can review the listing associated with that business.