She was best known as the original English dub voice of the title characters of the 1960s anime series Astro Boy and Kimba the White Lion, the character Elsie the Cow for Borden Cheese's television commercials, and a live-action turn playing Ellie Harper Bergman on the soap opera Search for Tomorrow.

[2] Watt's first regular role on television had her portraying the girlfriend of the title character in The Billy Bean Show (1949,[3] 1951).

Ladd's cast remained close during Watt's career, including her friend Ray Owens, his wife Sonia, and Gilbert Mack.

Later in life, Watt's voice was heard by radio listeners of In-Touch Networks who are visually impaired or completely blind.

Watt's final acting role was the voice of Ma Bagge (Eustace's mother) on the series Courage the Cowardly Dog from 1999 to 2001.