| SERAGIO 1099974 · TMA608164 | Kia Corporation | 12 Vehicles | Registered | 2004 |
| SERKO 2033272 · TMA1164275 | Serko Limited | 9 Electronics35 Advertising39 Transport+1 | Registered | 2023 |
| SERCO 1876014 · TMA1071221 | an individual | 6 Metal7 Machines9 Electronics+3 | Registered | 2020 |
| SARZIO 1863110 · TMA1038599 | an individual | 5 Pharmaceuticals | Registered | 2019 |
| SERCO 1216431 · TMA680031 | SERCO GROUP PLC | 35 Advertising37 Construction38 Telecommunications+6 | Registered | 2007 |
| SERCO 1113428 · TMA675423 | SERCO GROUP PLC | 35 Advertising37 Construction38 Telecommunications+7 | Registered | 2006 |
| SERCO 0350663 · TMA189697 | an individual | 2 Paints6 Metal7 Machines+10 | Registered | 1973 |
| SERGE 2254678 | Owner not listed | 15 Musical | Pending | 2023 |
| SERGE 2060279 · design | Serge Island Dairies Limited | 29 Meat | Pending | 2020 |
| SERGE 2060278 | Serge Island Dairies Limited | 29 Meat | Pending | 2020 |
| SERCO 2051979 | an individual | 7 Machines12 Vehicles35 Advertising+2 | Pending | 2020 |
| SERIOUS 1668744 · TMA980882 | Unilever Global IP Limited | 3 Cosmetics | Registered | 2017 |
| SERIOUS: 1612194 · TMA937437 | Serious Labs Inc. | 9 Electronics16 Paper41 Education+1 | Registered | 2016 |
| SERESCO 1193409 · TMA634877 · design | SOLUTIONS D'AIR DÉSHUMIDIFIÉ INC./DEHUMIDIFIED AIR SOLUTIONS INC. | 11 Lighting42 Science | Registered | 2005 |
| SERESCO 2221712 | DEHUMIDIFIED AIR SOLUTIONS INC. | 11 Lighting42 Science | Pending | 2022 |
| SORRISO 2137425 | 2065420 Alberta Ltd. | 32 Beer | Pending | 2021 |
| SORRISO 1977980 | Broan-NuTone LLC, a Delaware limited liability company | 11 Lighting | Pending | 2019 |
| SKYRISE 2268867 · TMA1285040 | IGT | 28 Toys | Registered | 2025 |
| SHARGE 2242434 · TMA1261731 · design | Sharge Technology (Shenzhen) Co. LTD | 9 Electronics | Registered | 2024 |
| SIRCA 2241547 · TMA1257038 | STRYKER CORPORATION | 10 Medical | Registered | 2024 |
| SharX-5 2239271 · TMA1259895 | AXL ELECTRIC VEHICLES INC. | 12 Vehicles | Registered | 2024 |
| Skorch 2234942 · TMA1256759 | Annie D. Enterprises Incorporated/Annie D. Entreprises Incorporée | 32 Beer35 Advertising39 Transport+1 | Registered | 2024 |
| 1500 SERIES 2231250 · TMA1255155 | Hanchett Entry Systems, Inc. | 9 Electronics | Registered | 2024 |
| 1600 SERIES 2231249 · TMA1255154 | Hanchett Entry Systems, Inc. | 9 Electronics | Registered | 2024 |
| 1100 SERIES 2215062 · TMA1202039 | Green Manufacturing, Inc. | 7 Machines | Registered | 2023 |