WPP is a British multinational communications, advertising, public relations, technology, and commerce holding company headquartered in London, England. It is considered the world's largest advertising company, as of 2019. WPP plc owns many companies, which includes advertising, public relations, media, and market research networks such as AKQA, BCW, Essence Global, Finsbury, Grey, Hill+Knowlton Strategies, Mindshare, Ogilvy, Wavemaker, Wunderman Thompson, and VMLY&R. It is one of the "Big Four" agency companies, alongside Publicis, Interpublic Group of Companies and Omnicom. WPP has a primary listing on the London Stock Exchange and is a constituent of the FTSE 100 Index. It has a secondary listing on the New York Stock Exchange.
On 14 April 2018, Martin Sorrell retired 33 years after founding the company. Roberto Quarta is chairman. Mark Read is CEO.