| Sam Lave Auto | Car Washes | — |
| Samson Belair Deloitte | Accounting Services | facebook.com |
| Samv Transport Inc | Bus & Coach Rental & Charter | facebook.com |
| Sandman Hotel Montréal-Longueuil | Tout Tourisme et hôtels | sandmanhotels.com |
| Santé Canada - Programme de l'Inspectorat | Business Centres | hc-sc.gc.ca |
| Santé Mobile | Medical Clinics | voyages-turquoise.com |
| SAP Delage Inc | Bookkeeping | — |
| SAQ Mini Agence - Couche-Tard Inc. | Beer & Ale | saq.com |
| SAQ Sélection-Carrefour St-Hubert | Beer & Ale | saq.com |
| SAQ-Longueuil - Ch. de Chambly | Beer & Ale | saq.com |
| SAQ-Place Longueuil | Beer & Ale | saq.com |
| Scardera Inc | Baskets | scardera.com |
| SCI Logistics | Cold-Storage Warehouses | facebook.com |
| Scintillant comme un gant! | Cleaning Services, Cleaning Service | — |
| Scripto Centris Inc | Computer Networking | sc.ca |
| SDEM-SEMO | Tout Entreprises et services | sdem-semo.org |
| Sedex Lab Inc. | Tout Entreprises et services | sedexlab.com |
| Sengchanh Phommaphavahn Ac | Acupuncturists | acupuncture-sengchanh.ca |
| Sequoia Massothérapie inc. Succursale Longueuil | Massage Therapy | sequoialongueuil.com |
| Serge Lavoie Ltd | Not Profit, Grocery Stores | facebook.com |
| Service Comptable D.R.L | Bookkeeping Software & Accounting Systems | facebook.com |
| Service Comptable Montérégie Inc. | Bookkeeping | — |
| Service De Garde - Les Petits Jardiniers | Childcare Services | — |
| Service de plomberie chauffage FC | Plumbing | — |
| Service Gagnon Electrique inc. | Tout Entreprises et services | servicegagnonelectrique.com |
| Service Santé Massokiné | Massage Therapy | massokine.ca |
| Services aux arrondissements | Not Profit, library, Library | — |
| Services Bravo | Business Centres | facebook.com |
| Services Comptables du Vieux Longueuil | Bookkeeping | comptable-longueuil.ca |
| Services Fiscaux Optimum Inc | Bookkeeping | facebook.com |
| Services Maximum | Cleaning Services, Cleaning Service | servicesmaximum.ca |
| Services PB | Tout Entreprises et services, Tout Informatique et internet | servicespb.ca |
| Services Santé Nancy Langlois - Massothérapie Saint-Hubert | Massage Therapy | 411sante.com |
| Services Vitrolcean | Cleaning Services, Cleaning Service | — |
| Servisante | Allergy Medications & Services | — |
| Sexe Shop Erotico Longueuil | Beauty & Fitness, Hairdressers & Beauty Salons | — |
| Sherlock Antitheft Marking Inc | Answering Machines & Equipment | sherlock.ca |
| Sherman Jack Dr | Dentists | — |
| Shu Yu | yu | — |
| SID Distribution Inc. | Tout Informatique et internet | sid-dis.com |
| Sigma Impôts | Accountants | facebook.com |
| Signalisation S.A.I.C. Inc. | Tout Entreprises et services | saic.ca |
| Signé Cyril Coiffure | Beauty & Fitness, Hairdressers & Beauty Salons | signecyrilcoiffure.ca |
| Silva Grillades | Tout Bars et restaurants | — |
| Simcom Inc | Advertising Agencies | facebook.com |
| Simon Melançon, Kinésithérapeute-kinésiologue | Massage Therapy | facebook.com |
| Sky Mobilite | Answering Machines & Equipment | — |
| Sman Communications | Communications & Public Relations Consultants | facebook.com |
| Smart Set | Clothing Stores | facebook.com |
| Societe Dentaire De Montreal | Dentists | — |
