WPP plc is a British multinational communications, advertising, public relations, technology, and commerce holding company headquartered in London, England. It is the world's largest advertising company, as of 2023. WPP plc owns many companies, which include advertising, public relations, media, and market research networks such as AKQA, BCW, CMI Media Group, EssenceMediacom, Grey, Hill & Knowlton, Mindshare, Ogilvy, VML, Wavemaker, and WPP Media. It is one of the "Big Four" agency companies, alongside Publicis, The Interpublic Group of Companies, and Omnicom Group. WPP has a primary listing on the London Stock Exchange, and is a constituent of the FTSE 100 Index. Wikipedia