Andreessen Horowitz is a private American venture capital firm, founded in 2009 by Marc Andreessen and Ben Horowitz. The company is headquartered in Menlo Park, California. As of April 2023, Andreessen Horowitz ranks first on the list of venture capital firms by assets under management, with $42 billion as of May 2024.

Marc Lowell Andreessen is an American businessman and former software engineer. He is the co-author of Mosaic, the first widely used web browser with a graphical user interface; co-founder of Netscape; and co-founder and general partner of Silicon Valley venture capital firm Andreessen Horowitz. He co-founded and later sold the software company Opsware to Hewlett-Packard. Andreessen is also a co-founder of Ning, a company that provides a platform for social networking websites and an inductee in the World Wide Web Hall of Fame. Andreessen's net-worth is estimated at $1.7 billion.