The largest brokerages in Sarnia
4 offices, 202 agents counted at the 2026-09-23 scan. REMAX Sarnia Realty Inc leads with 115 agents — 56.9% of the tracked roster, ahead of Coldwell Banker Southwest Realty, Brokerage at 45. The local market is unusually concentrated — three offices hold most of it (top three hold 97.5%).
The top 4 at a glance
Agents on the roster at the 2026-09-23 scan; percentages are share of all 202 tracked in Sarnia.
- REMAX Sarnia Realty Inc 115 56.9%
- Coldwell Banker Southwest Realty, Brokerage 45 22.3%
- Royal LePage Key Realty 37 18.3%
- Coldwell Banker COMMERCIAL Southwest Realty. Brokerage 5 2.5%
Bar length is relative to the largest row; percentages are share of all 202 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 | 115 | 56.9% |
| 2 | Coldwell Banker Southwest Realty, Brokerage | Coldwell Banker | 45 | 22.3% |
| 3 | Royal LePage Key Realty | Royal LePage | 37 | 18.3% |
| 4 | Coldwell Banker COMMERCIAL Southwest Realty. Brokerage | Coldwell Banker | 5 | 2.5% |
Offices with fewer than 10 agents appear in this table but don't get their own page. Across the 115 Sarnia agents whose sites we check, 121.7% list a website of their own (national 59%).
Network mix in Sarnia
Coverage: these are the 3 national networks we scrape — about 46.1% 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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