| Ontario | |
|---|---|
| County Number | 52 |
| Postal abbr. | ON |
| Capital | Toronto |
| Nickname | Yours to Discover, The Heartland Province |
| ISO | CA-ON |
| FIPS | CA08 |
| Name | County | Postal Code |
|---|---|---|
| Newmarket | 3519 | L3X L3Y L4A |
| Windsor | 3537 | N8N N8P N8R N8S N8T N8V N8W N8X N8Y N9A N9B N9C N9E N9G N9H N9J N9K |
| Limehouse | 3524 | L0P |
| Loretto | 3543 | L0G |
| Oil City | 3538 | N0N |
| Morrisburg | 3501 | K0C |
| Nanticoke | 3528 | N0A |
| Linwood | 3530 | N0B |
| Commanda | 3549 | P0H |
| Hagar | 3552 | P0M |
| Name | State |
|---|---|
| Stormont, Dundas and Glengarry | Ontario |
| Hastings | Ontario |
| Kenora | Ontario |
| Huron | Ontario |
| Simcoe | Ontario |
| Thunder Bay | Ontario |
| Perth | Ontario |
| York | Ontario |
| Leeds and Grenville | Ontario |
| Lanark | Ontario |
| Dufferin | Ontario |
| Prescott and Russell | Ontario |
| Lennox and Addington | Ontario |
| Sudbury | Ontario |
| Algoma | Ontario |
| Essex | Ontario |
| Peterborough | Ontario |
| Renfrew | Ontario |
| Cochrane | Ontario |
| Grey | Ontario |