Jimmy Donal "Jimbo" Wales (born August 7, 1966) is an American Internet entrepreneur and former financial trader. Most notably, he co-founded Wikipedia, a nonprofit free encyclopedia, and Fandom (formerly Wikia), a for-profit wiki hosting service. He has also worked on Bomis, Nupedia, WikiTribune, and Trust Café (formerly WT Social).

Born in Huntsville, Alabama, Wales attended Randolph School and earned finance degrees from Auburn University and the University of Alabama. While in graduate school, he taught at two universities, but left before completing a PhD to work in finance, later becoming chief research officer at Chicago Options Associates.

In 1996, he co-founded Bomis, which funded the free peer-reviewed encyclopedia Nupedia (2000–2003). On January 15, 2001, with Larry Sanger and others, he launched Wikipedia, which grew rapidly. Wales became its promoter and public face, though he has at times disputed Sanger's role, claiming sole founder status.

Wales has served on the Wikimedia Foundation Board of Trustees since its creation, holding its board-appointed "community founder" seat. He gives annual "State of the Wiki" addresses at Wikimania. For his role in creating Wikipedia, Time named him one of the 100 most influential people in the world in 2006.

Wales was born in Huntsville, Alabama, on August 7, 1966; however, his birth certificate lists his date of birth as August 8. His father, Jimmy Sr., was a grocery store manager, while his mother, Doris Ann (née Dudley), and his grandmother, Erma, ran the House of Learning, a small private school in the tradition of the one-room schoolhouse, where Wales and his three siblings received their early education.

As a child, Wales enjoyed reading. When he was three years old, his mother bought a World Book Encyclopedia from a door-to-door salesman. World Book sent out stickers for owners to paste on the pages to update the encyclopedia, and Wales used them on his copy, stating, "I joke that I started as a kid revising the encyclopedia by stickering the one my mother bought."

During an interview in 2005 with Brian Lamb, Wales described his childhood private school as a "Montessori-influenced philosophy of education", where he "spent lots of hours poring over the Britannica and World Book Encyclopedias". There were only four other children in Wales' grade, so the school combined the first- through fourth-grade students, and the fifth- through eighth-grade students. As an adult, Wales was sharply critical of the government's treatment of the school, citing the "constant interference and bureaucracy and very sort of snobby inspectors from the state" as a formative influence on his political philosophy.

After eighth grade, Wales attended Randolph School, a university-preparatory school in Huntsville, graduating at age 16. He said that the school was expensive for his family, but that "education was always a passion in my household ... you know, the very traditional approach to knowledge and learning and establishing that as a base for a good life." He received his bachelor's degree in finance from Auburn University in 1986. He began his Auburn education when he was 16 years old. He then entered the PhD finance program at the University of Alabama before leaving with a master's degree to enter the PhD finance program at Indiana University Bloomington. At the University of Alabama, he played Internet fantasy games and developed his interest in the web. He taught at both universities during his postgraduate studies but did not write the doctoral dissertation required for a PhD, something he ascribed to boredom.