Three UK
 | |
| Three UK | |
| Type | Limited company |
| Industry | Telecommunications |
| Founded | 3 March 2003 |
| Founder | Hutchison Whampoa |
| Headquarters | Reading, Berkshire, England, UK |
Number of locations | 293 stores |
Area served | United Kingdom |
| Key people | Max Taylor (CEO) |
| Products | |
| Brands | SMARTY |
| Services | Broadband and Mobile |
| Revenue |  £2,590 million (FY 2023) |
Number of employees | 4,800 |
| Parent | VodafoneThree |
| Website | www |
Hutchison 3G UK Limited, trading as Three UK, is a British telecommunications company based in Reading, Berkshire, England. It is a part of VodafoneThree, a subsidiary of Vodafone. It is the smallest of the four mobile network operators in the United Kingdom, with about 10.9 million subscribers as of November 2024, behind fellow VodafoneThree subsidiary Vodafone UK.
The service was launched by CK Hutchison Holdings on 3 March 2003 as the UK's first commercial 100% 3G network. It provides 4G and 5G services through its own network infrastructure. In June 2023, it was proposed that Three would merge with Vodafone UK. The merger was approved by the Competition and Markets Authority in December 2024 and completed in June 2025. CK Hutchison agreed in May 2026 to sell its whole stake in the business to Vodafone Group and the transaction completed on 30 July 2026, making VodafoneThree a wholly owned subsidiary of Vodafone Group.