Andrews joins from Edelman, where she was group new business director, managing director.
Her arrival to the newly-created role at Grayling comes after a "year of significant growth" for the UK business. She will be based in London and focused on building both domestic and international clients.
Prior to joining Edelman in 2016, Andrews was a new business director at Publicis's MSL Group, helping win clients including Coca-Cola and Netflix, and before that managing director of marcomms at Hill + Knowlton and a director at Ketchum.
Sarah Scholefield, chief executive of Grayling UK & Ireland, said Andrews would help the agency realise plans to grow across the UK and Europe. "There is a real opportunity for us to open a dialogue and partner with companies looking to connect with new audiences across multiple channels, cultures and countries and we’re excited to have Bronwen leading this charge," she said.
Jan Simunek, chief executive of Grayling Continental Europe, added that Andrews would help the agency reach decision makers at companies looking for integrated multi-country comms strategies.