| .it | Country Code | IIT - CNR | 🇮🇹Italy | — |
| .itau | Generic | Itau Unibanco Holding S.A. | — | — |
| .itv | Generic | ITV Services Limited | — | — |
| .jaguar | Generic | Jaguar Land Rover Ltd | — | — |
| .java | Generic | Oracle Corporation | — | — |
| .jcb | Generic | JCB Co., Ltd. | — | — |
| .je | Country Code | Island Networks (Jersey) Ltd. | 🇯🇪Jersey | — |
| .jeep | Generic | FCA US LLC. | — | — |
| .jetzt | Generic | Binky Moon, LLC | — | — |
| .jewelry | Generic | Binky Moon, LLC | — | — |
| .jio | Generic | Reliance Industries Limited | — | — |
| .jll | Generic | Jones Lang LaSalle Incorporated | — | — |
| .jm | Country Code | University of West Indies | 🇯🇲Jamaica | — |
| .jmp | Generic | Matrix IP LLC | — | — |
| .jnj | Generic | Johnson & Johnson Services, Inc. | — | — |
| .jo | Country Code | Ministry of Digital Economy and Entrepreneurship (MoDEE) | 🇯🇴Jordan | — |
| .jobs | Sponsored | Employ Media LLC | — | — |
| .joburg | Generic | ZA Central Registry NPC trading as ZA Central Registry | — | — |
| .jot | Generic | Amazon Registry Services, Inc. | — | — |
| .joy | Generic | Amazon Registry Services, Inc. | — | — |
| .jp | Country Code | Japan Registry Services Co., Ltd. | 🇯🇵Japan | — |
| .jpmorgan | Generic | JPMorgan Chase Bank, National Association | — | — |
| .jprs | Generic | Japan Registry Services Co., Ltd. | — | — |
| .juegos | Generic | Dog Beach, LLC | — | — |
| .juniper | Generic | JUNIPER NETWORKS, INC. | — | — |
| .kaufen | Generic | Dog Beach, LLC | — | — |
| .kddi | Generic | KDDI CORPORATION | — | — |
| .ke | Country Code | Kenya Network Information Center (KeNIC) | 🇰🇪Kenya | — |
| .kerryhotels | Generic | Kerry Trading Co. Limited | — | — |
| .kerryproperties | Generic | Kerry Trading Co. Limited | — | — |
| .kfh | Generic | Kuwait Finance House | — | — |
| .kg | Country Code | AsiaInfo Telecommunication Enterprise | 🇰🇬Kyrgyzstan | — |
| .kh | Country Code | Telecommunication Regulator of Cambodia (TRC) | 🇰🇭Cambodia | — |
| .ki | Country Code | Ministry of Information, Communications and Transport (MICT) | 🇰🇮Kiribati | — |
| .kia | Generic | KIA MOTORS CORPORATION | — | — |
| .kids | Generic | DotKids Foundation Limited | — | — |
| .kim | Generic | Identity Digital Limited | — | — |
| .kindle | Generic | Amazon Registry Services, Inc. | — | — |
| .kitchen | Generic | Binky Moon, LLC | — | — |
| .kiwi | Generic | DOT KIWI LIMITED | — | — |
| .km | Country Code | Comores Telecom | 🇰🇲Comoros | — |
| .kn | Country Code | Ministry of Finance, Sustainable Development Information & Technology | 🇰🇳Saint Kitts and Nevis | — |
| .koeln | Generic | dotKoeln GmbH | — | — |
| .komatsu | Generic | Komatsu Ltd. | — | — |
| .kosher | Generic | Kosher Marketing Assets LLC | — | — |
| .kp | Country Code | Star Joint Venture Company | 🇰🇵North Korea | — |
| .kpmg | Generic | KPMG International Cooperative (KPMG International Genossenschaft) | — | — |
| .kpn | Generic | Koninklijke KPN N.V. | — | — |
| .kr | Country Code | Korea Internet & Security Agency (KISA) | 🇰🇷South Korea | — |
| .krd | Generic | KRG Department of Information Technology | — | — |