| HODOR 1783834 · TMA972085 | Home Box Office, Inc. | 21 Housewares25 Clothing28 Toys | Registered | 2017 |
| HYDROW 2180744 · TMA1211354 | Hydrow, Inc. | 25 Clothing | Registered | 2023 |
| HYDROW 1955222 · TMA1231900 | Hydrow, Inc. | 9 Electronics28 Toys | Registered | 2024 |
| HYDURA 0357494 · TMA218038 | THE OILGEAR COMPANY | 7 Machines | Registered | 1976 |
| HYDRO 2158318 · TMA1266816 | Hydro Brand, Inc. | 4 Oils34 Tobacco | Registered | 2024 |
| HYDRA 2095143 · TMA1277237 | Byrne Electrical Specialists, Inc. | 9 Electronics | Registered | 2024 |
| HYDRO 2066729 · TMA1213964 · design | Delaware Capital Formation, Inc. | 7 Machines9 Electronics42 Science | Registered | 2023 |
| HDR 1985712 · TMA1106522 | CONTINENTAL REIFEN DEUTSCHLAND GMBH | 12 Vehicles | Registered | 2021 |
| HYDRA 1937192 · TMA1146161 · design | GAF Materials LLC | 19 Building | Registered | 2022 |
| HYDRY 1937191 · TMA1128194 | GAF Materials LLC | 19 Building | Registered | 2022 |
| HDR 1785322 · TMA990854 · design | HDR, Inc. | 42 Science | Registered | 2018 |
| HDR 1785321 · TMA990853 | HDR, Inc. | 42 Science | Registered | 2018 |
| HYDRA 1779371 · TMA981369 · design | an individual | 38 Telecommunications42 Science | Registered | 2017 |
| HYDRA 1771919 · TMA1041977 | MPDV Mikrolab GmbH | 9 Electronics35 Advertising42 Science | Registered | 2019 |
| HYDRA + 1649803 · TMA954410 | INDUSTRIES LASSONDE INC. | 29 Meat32 Beer | Registered | 2016 |
| HYDRA 1639279 · TMA891453 | EIKON DEVICE INC. | 8 Hand | Registered | 2014 |
| HYDRO 1638518 · TMA939343 | Kyocera International, Inc. | 9 Electronics | Registered | 2016 |
| HDR 1628008 · TMA894933 | THE AMES COMPANIES, INC. | 21 Housewares | Registered | 2015 |
| HYDRA 1491793 · TMA801310 | The Henry W.T. Mali & Co. Inc. | 24 Textiles | Registered | 2011 |
| HYDRA 1459071 · TMA799459 · design | Hydra Professionals, LLC | 35 Advertising36 Finance45 Legal | Registered | 2011 |
| HYDRA 1430917 · TMA776928 | Hydra Leatherland Inc. | 14 Jewellery18 Leather25 Clothing | Registered | 2010 |
| HYDRO 1412846 · TMA807398 | Edgewell Personal Care Brands, LLC | 8 Hand | Registered | 2011 |
| HDR 1407507 · TMA778494 | Voxx International Corporation, a Delaware corporation | 9 Electronics12 Vehicles | Registered | 2010 |
| HYDRO + 1380751 · TMA788444 | OMS Investments, Inc. (a Delaware corporation) | 1 Chemicals | Registered | 2011 |
| HYDRO 1300934 · TMA765643 | an individual | 9 Electronics | Registered | 2010 |