Watts is joining previously announced cast member Russell Crowe who will play Ailes reported variety.com.
Carlson rose to prominence over a decade ago at Fox News first as a co-anchor at "Fox and Friends" before going on to anchor her own show "The Real Story". She then became the first of multiple women to file a sexual harassment suit against Ailes after leaving Fox News.
The series is based on Gabriel Sherman s bestselling book "The Loudest Voice in the Room".
Sherman co-wrote the first episode of the series with "Spotlight" writer and director Tom McCarthy.
--IANS rb/bg
