Weed, who becomes the first marketer to take the newly-created prize, was voted for by 36% of the 6,000-strong public vote across the marketing industry.
The Global Marketer of the Year award was launched by the WFA to recognise those global and regional marketers who drive more effective and sustainable marketing.
Weed was one of six nominees for the award, and fended off competition from P&G's Marc Pritchard, Mastercard's Raja Rajamannar, Mars's Jane Wakely, Huawei's Glory Zhang and Deutsche Telekom's Hans-Christian Schwingen.
Contenders had to demonstrate their efforts in making their organisations more people-centric by building more engaged, happier teams; how they collaborate with agencies and vendors to be aligned to the same goals; and how their work genuinely makes a cultural or social difference to the business.
Weed said: "It’s an honour to be named as the first WFA Global Marketer of the Year. This is a wonderfully exciting time to be in marketing, and this award reflects the hard work and dedication of the whole team at Unilever. We have a clear purpose – to make sustainable living commonplace, and it is our talented marketers who are key to bringing that message alive to our consumers, and helping to drive long-term sustainable growth for Unilever."
David Wheldon, WFA president and the chief marketing officer of RBS, added: "A big congratulations to Keith on behalf of the global marketing industry. At a time when our industry is facing serious challenges, Keith has shown immense leadership. He is the purveyor of a portfolio of some of the world’s most purposeful brands, the architect of the Unstereotype Alliance and has been a pioneer in pushing for a better online advertising ecosystem."
The shortlist was drawn up by a jury of marketers following nominations made by more than 30 company members of the WFA.