Amazon Prime video will also soon support the Google Chromecast, ending a streaming spat between the two tech giants that started in 2017.
Google pulled its YouTube app from Amazon's Fire TV and Echo Show in December 2017 as competition between the two companies began to heat up in the streaming space.
At the time, Google said it decided to remove the app due to a "lack of reciprocity" from Amazon. It said Amazon refused to sell Google products such as the Google Home speaker, a competitor with the Amazon Echo, and the Nest camera, which competes with Amazon's Ring system. Amazon still does't sell the Google Home, but it does sell Nest cameras and thermostats.
Fire TV users have been able to use a third-party YouTube app that simply linked folks to the YouTube website. But a new version should offer a more feature-rich experience with support for 4K HDR content.
The addition of YouTube TV also means customers who subscribe to Google's streaming TV service will be able to tune in on the Fire TV, which supports additional services including Hulu, Sony's PS Vue, AT&T DirecTV Now and Sling TV.