In her new role, Snowdon will oversee all Maxus branding, marketing and communications efforts, both internally and externally.
She will also work with the agency's worldwide business development director, Karen Kaufman, on new business development and pitch coordination.
She will be based in London and will report to Kelly Clark, worldwide chief executive of Maxus.
Prior to taking the role at Maxus, Snowdon was global marketing and communications director at PHD Group and had held business development roles at Starcom MediaVest and fellow WPP network, Mindshare.
Clark said: "Helena's appointment is a major commitment to building the Maxus brand with clients, new business prospects, pitch consultants, and the media. I'm delighted she's joining us. She's smart, fun to work with, and gets things done. She will fit right in here."
.jpg)
.jpg)