Capital TV is now available at Sky channel 388 and Freesat 517, while Heart TV can be accessed on Sky 387 and Freesat 516.
The channels can also be watched via dedicated iPhone and iPad apps, along with online via heart.co.uk and capitalfm.com.
Announcing the two TV channels in July, Global Radio founder Ashley Tabor said that they would 'deepen and enhance' the brand identities of Heart and Capital, and target the same demographics as the two stations.
In a statement today, Global said that Capital TV and Heart TV represent "the next generation in music television", including Capital focusing on the latest hits from the biggest artists now, and Heart reminding viewers of "some of the greatest videos ever made".
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Both channels will play non-stop music videos 24 hours a day, 7 days a week. There will also be some exclusive content, such as Capital's Jingle Bell Ball.
Tabor said that Global "prides itself" on offering clear and simple brand propositions to consumers.
"We want our brands to lead the way in delivering great content to people wherever and however they enjoy music, and the launch of Heart TV and Capital TV is the next step in deepening and extending the relationship we've already built with our audiences," he said.
"These channels are absolutely stunning, they look gorgeous, are incredibly slick and represent the next generation of music TV channels. The team here at Global have done a fantastic job."
Global Group chief executive Stephen Miron added: "The launch of these new TV channels are a natural evolution for the Capital & Heart brands and will allow us to provide increased commercial opportunities for our radio partners."