Definition: A person who represents a company, industry or cause in the media .
A spokesperson is usually a member of a company's marketing department, another company employee (the CEO or a corporate communications director), or a member of a public relations firm hired by the company. Their task is to present a professional "face" and consistent message for the company in media interviews.
A spokesperson can also be a celebrity hired to increase the visibility or reputation of a company in the media. Additionally, industries often have spokespeople who are experts called upon by press to represent said industry.