| Ottawa Jhikli Ambwari | India Standard Time | -10:30 |
| Ottawa Jessup | Eastern Time | 00:00 |
| Ottawa Jesus Maria | Peru Time | 00:00 |
| Ottawa Jette | Central European Time | -06:00 |
| Ottawa Jettingen-Scheppach | Central European Time | -06:00 |
| Ottawa Jindalee | Eastern Australia Time | -15:00 |
| Ottawa Jindivick | Eastern Australia Time | -16:00 |
| Ottawa Jim Thorpe | Eastern Time | 00:00 |
| Ottawa Jinan | China Time | -13:00 |
| Ottawa Ironton | Eastern Time | 00:00 |
| Ottawa Iruma | Japan Time | -14:00 |
| Ottawa Ireland | United Kingdom Time | -05:00 |
| Ottawa Ipswich | Eastern Time | 00:00 |
| Ottawa Iowa Park | Central Time | 01:00 |
| Ottawa Iphofen | Central European Time | -06:00 |
| Ottawa Inzell | Central European Time | -06:00 |
| Ottawa Inverurie | United Kingdom Time | -05:00 |
| Ottawa Inverleigh | Eastern Australia Time | -16:00 |
| Ottawa Innaloo | Western Australia Time | -13:00 |
| Ottawa Intra | Central European Time | -06:00 |
| Ottawa Ingersoll | Eastern Time | 00:00 |
| Ottawa Ingleburn | Eastern Australia Time | -16:00 |
| Ottawa Inez | Eastern Time | 00:00 |
| Ottawa Inishmore | Ireland Time | -05:00 |
| Ottawa Indapur | India Standard Time | -10:30 |
| Ottawa Indiana | Eastern Time | 00:00 |
| Ottawa Indialantic | Eastern Time | 00:00 |
| Ottawa Indian Harbour Beach | Eastern Time | 00:00 |
| Ottawa Indian Rocks Beach | Eastern Time | 00:00 |
| Ottawa Imboden | Central Time | 01:00 |
| Ottawa Immenstadt | Central European Time | -06:00 |
| Ottawa Incline Village | Pacific Time | 03:00 |
| Ottawa Inala | Eastern Australia Time | -15:00 |
| Ottawa Inari | Eastern European Time | -07:00 |
| Ottawa Ischgl | Central European Time | -06:00 |
| Ottawa Irvine | Pacific Time | 03:00 |
| Ottawa Irvine | United Kingdom Time | -05:00 |
| Ottawa Irving | Central Time | 01:00 |
| Ottawa Ishikawa | Japan Time | -14:00 |
| Ottawa Issigeac | Central European Time | -06:00 |
| Ottawa Islington | Eastern Australia Time | -16:00 |
| Ottawa Islamorada | Eastern Time | 00:00 |
| Ottawa Islamabad | Pakistan Time | -10:00 |
| Ottawa Islandia | Eastern Time | 00:00 |
| Ottawa Isle | Central Time | 01:00 |
| Ottawa Isla Canela | Central European Time | -06:00 |
| Ottawa Isla Mujeres | Eastern Time | 00:00 |
| Ottawa Itabashi | Japan Time | -14:00 |
| Ottawa Itatiaia | Brasilia Time | -02:00 |
| Ottawa Itaunja | India Standard Time | -10:30 |