The largest brokerages in Sarnia
8 offices, 213 agents counted at the 2026-11-02 scan. Some agents here are counted as of an earlier read: realtor.ca, last read August 18, 2026. REMAX Sarnia Realty Inc leads with 116 agents — 54.5% of the tracked roster, ahead of Coldwell Banker Southwest Realty, Brokerage at 47. The local market is unusually concentrated — three offices hold most of it (top three hold 94.8%).
The top 8 at a glance
Agents on the roster at the 2026-11-02 scan; percentages are share of all 213 tracked in Sarnia.
- REMAX Sarnia Realty Inc 116 54.5%
- Coldwell Banker Southwest Realty, Brokerage 47 22.1%
- Royal LePage Key Realty 39 18.3%
- Coldwell Banker COMMERCIAL Southwest Realty. Brokerage 5 2.3%
- Exit Realty Community 2 0.9%
- Exp Realty (branch not listed) 2 0.9%
- Initia Real Estate (Ontario) Ltd 1 0.5%
- Southwest Realty, Brokerage North Sarnia Office 1 0.5%
Bar length is relative to the largest row; percentages are share of all 213 tracked agents. Download this chart as an image ↓
Every office we track in Sarnia
| # | Office | Network | Agents | Share |
|---|---|---|---|---|
| 1 | REMAX Sarnia Realty Inc | RE/MAX | 116 | 54.5% |
| 2 | Coldwell Banker Southwest Realty, Brokerage | Coldwell Banker | 47 | 22.1% |
| 3 | Royal LePage Key Realty | Royal LePage | 39 | 18.3% |
| 4 | Coldwell Banker COMMERCIAL Southwest Realty. Brokerage | Coldwell Banker | 5 | 2.3% |
| 5 | Exit Realty Community | realtor.ca | 2 | 0.9% |
| 6 | Exp Realty (branch not listed) | realtor.ca | 2 | 0.9% |
| 7 | Initia Real Estate (Ontario) Ltd | realtor.ca | 1 | 0.5% |
| 8 | Southwest Realty, Brokerage North Sarnia Office | Coldwell Banker | 1 | 0.5% |
Offices with fewer than 10 agents appear in this table but don't get their own page. Across the 116 Sarnia agents whose sites we check, 127.6% list a website of their own (national 59.9%).
Network mix in Sarnia
Coverage: these are the 4 brokerage rosters we scrape (national networks and independents) — about 50.6% of Canadian REALTORS® nationally. Independents and brokerages outside those networks aren't counted, so read this as the largest offices among the networks we track in Sarnia. Methodology →
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