The Harris Poll is an American market research and analytics company that has been tracking the sentiment, behaviors and motivations of American adults since 1963. In addition to the traditional consulting offered, Harris has developed software data platforms that allow brands to track health and campaign success. The firm works with clients in three primary areas: brand strategy and tracking, corporate reputation, and research for public release.

The Harris Poll was started by Louis Harris, an opinion pollster who founded his own firm, Louis Harris & Associates, in 1956. Later rebranded Harris Interactive. The business was acquired from Nielsen in 2017 by the Stagwell Group, which hired co-Chief Executive Officers John Gerzema and Will Johnson, who relaunched the firm as The Harris Poll. Stagwell Founder and Managing Director Mark Penn also serves as Chairman as well as CEO of MDC Partners. The Harris Poll is headquartered in Chicago and New York City, with additional offices in Washington, D.C., and Rochester, New York.

The Harris Poll runs the longest-standing and largest data set on public opinion research on the coronavirus pandemic in the United States through its COVID-19 Tracker, a biweekly online survey of a nationally representative sample of American adults.