The Interpublic Group of Companies, Inc. (NYSE: IPG) is a holding company for hundreds of marketing, advertising, and other business service companies around the globe. It is headquartered in New York City and is the parent company of McCann-Erickson, the largest advertising agency in the world.

IPG was created in 1960 as the first marketing services management holding company, with McCann-Erickson and McCann-Marschalk as its two subsidiaries. Since then, it has grown tremendously, with over 185 companies purchased in a two-year span from 1999 to 2001. Comparisons have been made to AOL Time Warner, as both are media conglomerates that have trouble managing their holdings. The advertising firm Campbell-Ewald is also a subsidiary of IPG.

In 2002, IPG suffered a precipitous drop in its stock price and reputation in an accounting scandal that was an epidemic among American companies (such as Enron, WorldCom, Tyco, and Adelphia) during that period.