Westwood One was an American radio network that was based in New York City. At one time, it was managed by CBS Radio, and was later purchased by the private equity firm, The Gores Group. Due to purchases, mergers and other forms of consolidation in the 1980s and 1990s, at one time or another, it had ownership stakes in or syndication rights to some of the most famous brands in network radio, including CBS, NBC, Mutual, CNN, Fox, and Unistar. The company was one of the largest producers and distributors of radio programming in the United States. It broadcast entertainment, news, weather, sports, talk, and traffic programming to about 7,700 radio stations across the United States. The company was the top provider of local traffic reports in the U.S. through its subsidiaries, Metro Networks, Shadow Broadcast Services, SmartRoute Systems, and Sigalert.com. Westwood One also offers weather services; originally using Accuweather, Westwood switched to The Weather Channel in 2009.

Oaktree Capital Management, through its Triton Media Group division, merged with Westwood One in October 2011. Triton then folded Westwood One into its Dial Global subsidiary. The Westwood One name was initially retained for most sports programming. However, starting with the 2011–12 NFL playoffs, Westwood One's sports programming was branded as "Westwood One on the Dial Global Radio Network." After the NFL Playoffs concluded, the Westwood One name was removed altogether in favor of the Dial Global Sports Network, and the sports website was relocated to www.dialglobalsports.com.

On September 4, 2013, Dial Global announced that it was renaming itself Westwood One, citing greater brand recognition.