Shanks joined the agency as account director three years ago and became deputy MD, client services, in 2013. She has a background in recruitment advertising, with roles at companies including Prospectus and Peter Lockyer Advertising.
Theblueballroom, founded in 2001, has worked with a range of clients including Adidas, Coca-Cola Enterprises, DHL, Transport for London and Kingfisher.
Parry said: "I have enjoyed every minute of the last 15 years of Theblueballroom and I’m confident that now is the time to be handing over the reins to Kate. Theblueballroom is all about supporting organisations to respond to market forces, be flexible and embrace change. And this is exactly what we’re doing ourselves in ensuring we have next-generation leadership as we move into the next chapter of our story."
Shanks said: "I am not intending to make huge changes overnight, but we have to adapt with the needs of our clients."