He founded Elektra Records in his St. John's College dorm room in 1950 and Nonesuch Records in 1964. He signed such acts as Josh White, The Doors, Queen (US only), Love, Carly Simon, The Stooges, Harry Chapin, and Bread to Elektra and discovered folk singer Judy Collins. In 1970 he merged his music interests with Warner Communications (WCI) and continued his association with the labels he created for three additional years. While a part of the Warner Music Group, Holzman helped to establish both the WEA Distributing Corp (Warner-Elektra-Atlantic Distributing Corp) and WEA International.
In 1973, Holzman was appointed senior vice president and chief technologist for WCI. Holzman guided the company into home video and the first interactive cable television system, QUBE. Until 1972, he was a director of Pioneer Electronics Japan, helping that company, and Warner, adopt the compact disc and Laserdisc. Holzman was a member of the board of Atari, one of the first videogame companies, which was acquired by WCI in 1976.
In 1979 Holzman became the nexus between ex-Monkee Michael Nesmith and John Lack of Warner Cable. He persuaded Lack to meet with Nesmith who had been nursing an idea for a program he called PopClips. Holzman thought that Nesmith's notion of building a TV structure around that idea made real sense.
In 1982, following the death of President and founder Robert Gottschalk, Holzman took charge of Panavision, a wholly owned subsidiary of Warner Communications and turned that financially troubled company around.
In 1986 he formed FirstMedia, an investment firm which acquired Cinema Products Corporation, the maker of the Oscar winning Steadicam camera stabilization system.
In 1991, through FirstMedia, Holzman acquired the Discovery, Trend and Musicraft jazz labels from the estate of Albert Marx, which was also acquired by Warner Music Group in 1993.
After Edgar Bronfman, Jr. and a group of investors acquired Warner Music Group from Time Warner Inc. in 2004, Bronfman brought Holzman back to WMG, reuniting him with the company that he had helped to found with Ahmet Ertegun and Mo Ostin. Although Holzman's work at Warner Music covers a range from mentoring executives and future planning, his first project was the creation of an on-line label, Cordless Recordings, introduced in late 2005. Cordless gives bands space to hone their art and grow without the expectations and cash outlays associated with a major label.
In 2008 Holzman received the NARAS Grammy Trustees Award.
On December 15, 2010, it was announced that Holzman would be awarded the Ahmet Ertegun Award (along with Specialty Records founder Art Rupe) by the Rock and Roll Hall of Fame.
Holzman is the father of Adam Holzman, a jazz-rock keyboardist who has played with Miles Davis;Jaclyn Easton, a writer and Internet entrepreneur; and Marin Sander-Holzman, an editor and filmmaker.
Jac Holzman was inducted into the non-performer category of the Rock and Roll Hall of Fame on Monday, March 14, 2011.