Rachael MacFarlane (born 21 March 1976) is an American voice actress best known for her appearances in the FOX animated series Family Guy and American Dad!, both created and executive-produced by her older brother Seth MacFarlane. Rachel primarily provides the voice of Hayley, in addition to many other ancillary characters.
Aside from voice acting, MacFarlane has also been involved in other aspects of animation, such as being a production manager for The Grim Adventures of Billy and Mandy and Welcome to Eltingville. She also wrote an episode of Billy and Mandy, titled "Educating Grim".
On September 18, 2012, Rachael followed in her older brother's footsteps and released a big band album entitled Hayley Sings.