Los Angeles-based ad agency Walton Isaacson has appointed Christine Villanueva to the new role of executive vice president-brand, strategy and growth. The firm also hired GroupM veteran Tony Santabarbara as its new Chief Financial Officer.  

Villanueva is returning to the agency—she was previously Chief Strategy and Brand Officer from 2016 to 2021. She left to join Interpublic media agency UM where she served as U.S. Chief Strategy before launching her own consultancy in 2023.  

Santabarbara’s background includes seven years in finance roles at WPP’s GroupM. He served as Global CFO for Performance Media Group and Global CFO for Essence before shifting to U.S. CFO for EssenceMediacom. Earlier Santabarbara spent 18 years at Fox in finance and operations roles.  

Santabarbara succeeds Bill Braunstein, who joined Walton Isaacson as CFO in 2012 and will continue to serve in an advisory capacity.