WPP plc is a British multinational communications, advertising, public relations, technology, and commerce holding company headquartered in London, England. It was the world's largest advertising company, as of 2019.[4] WPP plc owns many companies, which includes advertising, public relations, media, and market research networks such as AKQA, BCW, CMI Media Group, 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.[5] WPP has a primary listing on the London Stock Exchange, and is a constituent of the FTSE 100 Index.[6]

On 14 April 2018, Martin Sorrell retired 33 years after founding the company. Roberto Quarta is chairman.[7] Mark Read is CEO.