IAC Inc. is an American holding company that owns brands across 100 countries, mostly in media and Internet. The company originated in 1996 as HSN Inc. as the holding company of Home Shopping Network and USA Network before changing its name to USA Networks, Inc. in 1999 and its television assets were sold to Vivendi in 2002. Those are now owned today by NBCUniversal, a division of Comcast.

The company is incorporated under the Delaware General Corporation Law but is headquartered in New York City. Joey Levin, who previously led the company's search and applications segment, served as chief executive officer from June 2015 until April 2025.

IAC was established in 1986 as Silver King Broadcasting Company, as part of a plan to increase viewership of the Home Shopping Network (HSN) by purchasing local television stations. By 1988, Silver King had bought 11 stations for about $220 million. The company was later renamed as HSN Communications, Inc., and then Silver King Communications, Inc. In 1992, Silver King was spun off to HSN shareholders as a separately traded public company with the Nasdaq stock ticker SKCI. In August 1995, Barry Diller acquired control of Silver King, in a deal backed by the company's largest shareholder, Liberty Media. Diller, who had led the creation of the Fox network, reportedly hoped to use Silver King's stations as the foundation for a new broadcast network.

The company acquired several assets in the late 1990s. In December 1996, Silver King acquired an 80% stake in HSN for $1.3 billion in stock, and changed its own name to HSN, Inc. At the same time, the company acquired Savoy Pictures, a failed film studio that owned four Fox affiliate stations through SF Broadcasting, for $210 million in stock.

HSN purchased a controlling stake in Ticketmaster Group in July 1997, and then acquired the rest of the company in June 1998. In February 1998, it acquired the television assets of Universal Studios (including USA Network, Sci-Fi Channel, and Universal Television's domestic production and distribution arms) for $4.1 billion. The company's name was changed to USA Networks, Inc. at this point. Continuing its acquisition strategy, the company acquired the Hotel Reservations Network in May 1999 for $149 million.

USA Networks merged the online division of Ticketmaster with city guide website Citysearch in September 1998, establishing a new company that went public as Ticketmaster Online–CitySearch (TMCS). USA then sold Ticketmaster proper to TMCS in 2001, retaining a 61 percent share in the combined company, which became known as simply Ticketmaster. USA brought Ticketmaster back under full ownership in 2003, purchasing all outstanding shares.

In the early 2000s, USA Networks began divesting itself of its traditional television broadcasting and production units. In May 2001, Univision Communications acquired USA Broadcasting (a division of USA Networks including 13 local stations). The next year, Vivendi bought the rest of USA's broadcast entertainment businesses, including the USA Network and Sci-Fi Channel. This led to the creation of a new company named Vivendi Universal Entertainment, led by Diller. Throughout this transition, USA Networks continued to build up its online portfolio. In July 2001, the company entered the online travel business with its acquisition of Expedia, followed the next year by an acquisition of Interval International.

Following the shift in focus to online assets, the company changed its name to USA Interactive (USAI) in May 2002; InterActiveCorp in June 2003; and finally to IAC/InterActiveCorp in July 2004.