| Lake Huron Coastal Centre, No Physical Address | Goderich |
| Landlord's Self Help Centre | Toronto |
| L'Arche Stratford | Stratford |
| Law Society of Ontario, Law Society Referral Service, Toronto | Toronto |
| Leads Employment Services, Stratford, Integrated Employment Services, Stratford | Stratford |
| Leduc Counselling Services, Leduc Couselling Services | Central Huron |
| Leukemia and Lymphoma Society of Canada - Ontario Region | North York East |
| LifeLabs, Listowel | Listowel |
| LifeLabs, Stratford | Stratford |
| Lifeline | Toronto |
| Lily Dempsey Women's Institute, North Perth - No Physical Address | North Perth |
| Lions Club of Monkton | North Perth |
| Lions Club of Stratford | Stratford |
| Lions Club, Milverton, Milverton, Lions Club of Milverton | Perth East |
| Listowel Agricultural Society | North Perth |
| Listowel Bible Chapel | North Perth |
| Listowel Christian School | North Perth |
| Listowel Community Church | North Perth |
| Listowel Curling Club | North Perth |
| Listowel Evangelical Missionary Church | North Perth |
| Listowel Horseshoes | North Perth |
| Listowel Mennonite Church | North Perth |
| Listowel Mental Health Outpatient Services | North Perth |
| Listowel Minor Baseball Association | North Perth |
| Listowel Minor Hockey Association | North Perth |
| Listowel Minor Soccer, Mailing Address | North Perth |
| Listowel Pentecostal Church | North Perth |
| Listowel Taxi | North Perth |
| Listowel Wingham Hospitals Alliance, Listowel Memorial Hospital | North Perth |
| Listowel Wingham Hospitals Alliance, Wingham and District Hospital | North Huron |
| Listowel-Wingham and Area Family Health Team, Listowel, Listowel-Wingham and Area Family Health Team - Listowel | North Perth |
| Listowel-Wingham and Area Family Health Team, North Perth Breastfeeding Clinic, Listowel | North Perth |
| Little Falls Co-operative Homes | St Marys |
| Loaves and Fishes Food Bank | Perth East |
| Loblaw Pharmacy, McDonald's Independent Grocery, St. Marys | St Marys |
| Lonely No More Program, No Physical Address, Virtual only | |