Weavers joins UM London from Vizeum, where she was the strategy director working on clients including BMW, Mini, 20th Century Fox and Kerry Foods.
Reporting to the UM chief executive, Andy Jones, and its chief strategy officer, Russell Place, Weavers will be responsible for UM's six-strong strategy team.
She arrives at UM with 20 years' experience that includes time spent at JWT, WCRS, CIA and the brand consultancy Branded. She also ran Element Communications, the now-defunct joint venture between Naked Communications and WCRS that handled the BMW media planning business before the account moved to Vizeum.
UM, which has recently added Marie Curie Cancer Care and South African Tourism to its client list, is set to pitch against Vizeum for the BMW business in March.