Oliver, who worked for Trimedia, now Grayling, earlier in her career, is taking over the strategy to grow Grayling’s consumer offer.
She replaces Kat McGettigan, who joined the agency in the same role last year.
McGettigan is now running Grayling's biggest global client account, Huawei, which it won earlier this year.
Oliver was head of consumer brands at Trimedia for nearly seven years, looking after drinks and telecoms clients.
She went on to become co-founder of consumer and social agency Fever, and a board director for the agency’s owner, Nelson Bostock.
After eight years with the group, Oliver moved to Nexus Communications, where she launched integrated creative agency Jolly Rebellion.
However, she left two years later to briefly join Kindred as a managing partner, before becoming an independent consultant.
Sarah Scholefield, Grayling's chief executive Europe, UK and Ireland, said the agency was already one year in to a three-year strategy aimed at "significantly" growing its consumer business, having hired McGettigan and creative and planning director Nathan Kemp last year.
Scholefield said: "We [won] arguably one of the biggest consumer accounts of the year, delivering significant growth in the Grayling business. As Kat moved across to manage this business, it felt the right time to hire someone like Frankie to take over leading our consumer business. She’s a champion for change and innovation: qualities we celebrate and encourage at Grayling."
She added: "Frankie is one of the early pioneers of integrated brand comms and has gone on to challenge the industry and her clients to produce better, more meaningful and effective work, while being known for creating working cultures that people thrive in."
Commenting on her move, Oliver said a lot had changed at the agency since she had joined it in its earlier guise.
She added: "I knew the minute I met Sarah that the time was right to rejoin. Not only have Sarah and Grayling’s chairman, Dickie Jukes, built a new and very talented leadership team, I’ve also been really impressed by their ambition and commitment to grow the consumer business."
Oliver said she was looking forward to working with McGettigan and Kemp, as well as the regional teams at Grayling’s eight UK offices.
"Together, we will lead a really exciting vision for the consumer business that will not only grow our offer in London and the regions, but will also act as a beacon for the best European and global briefs."