He replaces David Abraham, who stepped down in April this year to become the chief executive of Channel 4, and will start in September.
Childs has been on a director of UKTV since 2006.
The broadcaster is an independent commercial joint venture between BBC Worldwide and Virgin Media.
UKTV channels include Watch, Gold, Lifestyle and Blighty.
Childs says: “This is an exciting time to lead UKTV. Creating innovative new commercial models made available to broadcasters through the recent evolution in digital delivery and changes in audience demand will add further edge and continue to secure UKTV’s place as the owner and creator of must have brands for audiences, platforms advertisers and shareholders alike.”
The broadcaster has also named Jan Gooze-Zijl as its new chief financial officer. Gooze-Zijl will join in September from Virgin Media where he is currently finance director for planning.