| | Organization Name(s) | Located In |
 | L.H.A. Love Handles Anonymous | Victoria Harbour |
 | La Brie (Dr Joell) | Midland |
 | La Clé d'la Baie, Vague FM 88.1 | Penetanguishene |
 | La Clé d'la Baie en Huronie | Simcoe County |
 | La Clé d'la Baie en Huronie, Camp Bivouac, Summer Camp. Barrie, Borden and Penetanguishene Locations | Simcoe County |
 | La Clé d'la Baie en Huronie, Garderie le petit voilier - École élémentaire catholique Marguerite-Bourgeois | Borden CFB |
 | La Clé d'la Baie en Huronie, Garderie le petit voilier - École élémentaire Samuel-de-Champlain | Orillia |
 | La Clé d'la Baie en Huronie, Garderie Le petit voilier - École La Source | Barrie |
 | La Clé d'la Baie en Huronie, Garderie le petit voilier - École publique Saint-Joseph | Penetanguishene |
 | La Clé d'la Baie en Huronie, Garderie le petit voilier - École Saint-Louis | Penetanguishene |
 | La Clé d'la Baie en Huronie, Literacy and Basic Skills, Barrie | Barrie |
 | La Clé d'la Baie en Huronie, Literacy and Basic Skills, Penetanguishene | Penetanguishene |
 | La Clé d'la Baie en Huronie, Service à la petite enfance/Francophone Ontario Early Years Service | Penetanguishene |
 | La Clé d'la Baie en Huronie - Barrie, Le Coin des petits | Barrie |
 | La Clé d'la Baie en Huronie - La Clé de l'emploi/Employment Services, Ontario Employment Services, Penetanguishene | Penetanguishene |
 | La Clé d'la Baie en Huronie - Penetanguishene | Penetanguishene |
 | La Clé d'la Baie en Huronie. Le coin des petits. Penetanguishene | Penetanguishene |
 | La Leche League Canada. Midland/Penetanguishene Group | Midland |
| | Ladies of the Lake Conservation Association | Ontario |
 | Lafontaine Parish Hall | Lafontaine |
 | Lafontaine Park and Recreation Association | Lafontaine |
 | Lakehead Social Planning Council, 211 Ontario North | Thunder Bay |
 | Lakeview Cemetery. Midland | Midland |
 | Lakeview Towers Apartments | Midland |
 | Lalonde's Maple Syrup | Elmvale |
 | LAMP - ASK! Community Information Centre | Etobicoke South |
 | Landlord and Tenant Board, Toronto North District Office | Toronto |
 | Last Call Designated Driving Service | Barrie |
 | Laurentian University at Georgian, Orillia Campus | Orillia |
 | Laurin (Dr Daniel) | Midland |
 | Law Society of Upper Canada (The), Law Society Referral Service | Toronto |
 | Le Club de l'Âge d'Or de Lafontaine | Tiny |
 | Le Goût de vivre | Lafontaine |
 | Le Villageois de Lafontaine | Lafontaine |
 | Leaps and Bounds, Specialized Programming Service | York Region |
 | Learning Centres. Midland Campus | Midland |
 | Learning Centres. Midland Campus, Literacy and Basic Skills | Midland |
 | Learning Disabilities Association of Simcoe County | Simcoe County |
 | LeClair Cremation Centre | Midland |
 | Lefroy United Church | Innisfil |
 | Legal Aid Ontario, Central District Office | Barrie |
 | Legal Aid Ontario, Central District Office, Barrie Location, Advice Lawyer for Family Law | Barrie |
 | Legal Aid Ontario, Central District Office, Criminal Law Office | Barrie |
 | Legal Aid Ontario, Central District Office, Midland Location, Advice Lawyer for Family Law | Midland |
 | Leisureworld Caregiving Centre. Barrie | Barrie |
 | Lepage Fish Sales | Lafontaine |
| | Lesbian Gay Bi Trans Youth Line | Toronto |
| | LGBT Youth Connection Barrie | Barrie |
| | Library Garden Tour, North Simcoe | Simcoe North |
 | Lice Squad Canada | Innisfil |
| | Lice Wars Removal Force | Penetanguishene |
 | Life and Times News Magazine Group | Barrie |
 | Life Skills and Independence for Teens | Midland |
 | Lighthouse Christian Ministries | Orillia |
 | Lighthouse Christian Ministries, Emergency Shelter for Men | Orillia |
 | Links2Care, Acton Office | Acton |
| | Little Angels Lactation Support | Elmvale |
| | Little People of Ontario Inc | Ontario |
| | Liturgical Artists | Midland |
| | LIVESTRONG, Barrie Group | Barrie |
 | Living in Balance | Midland |
| | Liz Acs Home Care Services | Waubaushene |
 | Liz Frost. Group and Individual Psychotherapy | Tay |
 | Loiskandl (Dr Barbara), Laser Health Works | Midland |
 | Loiskandl (Dr Rainer), Laser Health Works | Midland |
| | Look Good Feel Better | Barrie |
| | Low-Income Energy Assistance Program (LEAP) | Ontario |
| | Low-Income Energy Assistance Program (LEAP), Simcoe County | Simcoe County |
 | Lu Robitaille Studio | Victoria Harbour |
 | Lupus Ontario | Markham |
 | Lynn-Stone Funeral Services | Elmvale |