Marc Russell Benioff (born September 25, 1964) is an American internet entrepreneur. He is best known as the co-founder, chairman and CEO of the software company Salesforce, as well as being the owner of Time magazine since 2018.

Marc Russell Benioff was born on September 25, 1964, in San Francisco, California. He is of Jewish heritage. He is the grandson of Marvin Lewis, a California trial attorney and member of the San Francisco Board of Supervisors who championed the creation of the Bay Area Rapid Transit (BART) system. Benioff grew up in Hillsborough and graduated from Burlingame High School in 1982. Benioff received a Bachelor of Science in business administration from the University of Southern California, where he was a member of the Tau Kappa Epsilon fraternity, in 1986.

While in high school, Benioff sold his first application, How to Juggle, for $75. In 1979, when he was 15, Benioff founded Liberty Software, creating and selling games such as Flapper and King Arthur's Heir for the Atari 8-bit. Royalties from these games helped Benioff pay for college.

While at USC, Benioff had an internship as a programmer at Apple where he wrote assembly code for the Macintosh. He joined Oracle Corporation in a customer-service role after graduating. Benioff worked at Oracle for 13 years in a variety of sales, marketing, and product development roles. At 23, he was named Oracle's Rookie of the Year, and later became the youngest vice president in the company's history.

Benioff founded Salesforce in 1999, while working from a San Francisco apartment. He defined its mission in a marketing statement as "The End of Software." This was a slogan he frequently used to preach about software on the Web; it was used too as a guerilla marketing tactic against the dominant CD-ROM-based customer relationship management (CRM) software provider at the time, Siebel. Benioff extended Salesforce's offerings in the early 2000s with the idea of a platform that allowed developers to create applications.

In November 2021, Benioff became co-CEO of Salesforce when Bret Taylor's promotion to co-CEO was announced. One year later, Bret Taylor stepped down as Salesforce co-CEO, leaving Marc Benioff as sole CEO again.

In January 2023 Benioff announced the mass dismissal of approximately 7,000 Salesforce employees via a two-hour all-hands meeting over a call, a course of action he later admitted had been a 'bad idea'. As of 2024, Salesforce is one of the biggest employers in San Francisco and the anchor tenant of Salesforce Tower, the tallest building in San Francisco.

In September 2025, Benioff reduced Salesforce's support workforce from 9,000 to about 5,000 employees because he "need[ed] less heads". Salesforce stated that AI agents now handle half of all customer interactions and have reduced support costs by 17% since early 2025. The decision contrasted with Benioff's earlier remarks suggesting that artificial intelligence would augment, rather than replace, white-collar workers. It follows similar workforce reductions at Microsoft and Klarna to automate human jobs.