Gabe Logan Newell (born November 3, 1962), also known by his nickname GabeN, is an American video game developer and businessman. He is the president and co-founder of the video game company Valve Corporation.

Newell was born in Colorado and grew up in Davis, California. He attended Harvard University in the early 1980s but dropped out to join Microsoft, where he helped create the first versions of the Windows operating system. In 1996, he and Mike Harrington left Microsoft to found Valve and fund the development of their first game, Half-Life (1998). Harrington sold his stake in Valve to Newell and left in 2000. Newell led the development of Valve's digital distribution service, Steam, which launched in 2003 and controlled most of the market for downloaded PC games by 2011.

As of 2021, Newell owned at least one quarter of Valve; Forbes estimated that he owned at least half as of 2025. He has been estimated as one of the wealthiest people in the United States and the wealthiest person in the video games industry, with an estimated net worth of $11 billion as of 2025. He is also the owner of the marine research organization Inkfish, the neuroscience company Starfish Neuroscience, and the custom yacht manufacturer Oceanco.

Newell was born on November 3, 1962, in Colorado, and attended Davis Senior High School in Davis, California. He began computer programming in high school, at a time when programming was not an established career path, and imagined he would become a doctor. He worked as a paperboy, and later a telegram messenger for Western Union. In 1980, Newell enrolled at Harvard University to study programming.

While at Harvard, Newell visited his brother at Microsoft, which was not yet a major software developer. At the suggestion of the Microsoft executive Steve Ballmer, he dropped out of Harvard and began working at Microsoft. Newell said later: "At the time it was the best place in the world to learn how to be a programmer ... Doing it at Microsoft was way better than going back and continuing my education at university."

Newell spent 13 years at Microsoft as a programmer and technical executive, and produced the first three releases of the operating system Windows. In late 1995, Doom, a 1993 first-person shooter game developed by id Software, was estimated to be installed on more computers worldwide than Microsoft's new operating system, Windows 95. Newell said: "[id] ... didn't even distribute through retail, it distributed through bulletin boards and other pre-internet mechanisms. To me, that was a lightning bolt. Microsoft was hiring 500-people sales teams and this entire company was 12 people, yet it had created the most widely distributed software in the world. There was a sea change coming." At Microsoft, Newell led development on a port of Doom for Windows 95, which is credited for helping make Windows a viable game platform.

Inspired by Michael Abrash, who left Microsoft to work on the game Quake at id, Newell and another employee, Mike Harrington, left Microsoft to found the video game company Valve on August 24, 1996. Newell opted to found Valve instead of retiring as he felt working with "other really smart, motivated, socially orientated people to create product that would affect millions of other people" was "the most fun I could have".

Newell and Harrington funded development of the first Valve game, the first-person shooter Half-Life (1998), which was a critical and commercial success. Harrington sold his stake in Valve to Newell in 2000. Newell gave Valve no deadline and a "virtually unlimited" budget to develop Half-Life 2 (2004), promising to fund it himself if necessary. He and Valve came close to bankruptcy during a legal battle with Vivendi Games, which ended when an intern discovered an email revealing that Vivendi was destroying evidence.