Edward Oakley Thorp (born August 14, 1932) is an American mathematics professor, author, hedge fund manager, and blackjack researcher. He pioneered the modern applications of probability theory, including the harnessing of very small correlations for reliable financial gain.

Thorp is the author of Beat the Dealer, which mathematically proved that the house advantage in blackjack could be overcome by card counting. He also developed and applied effective hedge fund techniques in the financial markets, and collaborated with Claude Shannon in creating the first wearable computer.

Thorp received his Ph.D. in mathematics from the University of California, Los Angeles in 1958, and worked at the Massachusetts Institute of Technology (MIT) from 1959 to 1961. He was a professor of mathematics from 1961 to 1965 at New Mexico State University. He then joined the University of California, Irvine where he was a professor of mathematics from 1965 to 1977 and a professor of mathematics and finance from 1977 to 1982.

Thorp was born in Chicago, but moved to southern California in his childhood. He had an early aptitude for science and often tinkered with experiments of his own creation. He was one of the youngest amateur radio operators when he was certified at age 12. Thorp went on to win scholarships by excelling in chemistry and physics competitions (one instance led him to meet President Truman), ultimately choosing to attend UC Berkeley for his undergraduate degree. However, he transferred to UCLA after one year, majoring in physics. This was eventually followed by a PhD in Mathematics at UCLA. He met his future wife Vivian during his first year at UCLA. They married in January 1956.^{[citation needed]}

Thorp used the IBM 704 as a research tool in order to investigate the probabilities of winning while developing his blackjack game theory, which was based on the Kelly criterion, which he learned about from the 1956 paper by Kelly. He learned Fortran in order to program the equations needed for his theoretical research model on the probabilities of winning at blackjack. Thorp analyzed the game of blackjack to a great extent this way, while devising card counting schemes with the aid of the IBM 704 in order to improve his odds, especially near the end of a card deck that is not being reshuffled after every deal.

Thorp decided to test his theory in practice in Reno, Lake Tahoe, and Las Vegas, Nevada. Thorp started his applied research using $10,000, with Manny Kimmel, a wealthy professional gambler and former bookmaker, providing the venture capital. First they visited Reno and Lake Tahoe establishments where they tested Thorp's theory at the local blackjack tables. The experimental results proved successful and his theory was verified since he won $11,000 in a single weekend. As a countermeasure to his methods, casinos now shuffle long before the end of the deck is reached. During his Las Vegas casino visits Thorp frequently used disguises such as wraparound glasses and false beards. In addition to the blackjack activities, Thorp had assembled a baccarat team which was also winning.

News quickly spread throughout the gambling community, which was eager for new methods of winning, while Thorp became an instant celebrity among blackjack aficionados. Due to the great demand generated about disseminating his research results to a wider gambling audience, he wrote the book Beat the Dealer in 1962 (substantially updated in 1966), widely considered the original guide to card counting, which sold over 700,000 copies, a huge number for a specialty title which earned it a place in the New York Times bestseller list, much to the chagrin of Kimmel whose identity was thinly disguised in the book as Mr. X.

Thorp's blackjack research is one of the very few examples where results from such research reached the public directly, completely bypassing the usual academic peer review process cycle. He has also stated that he considered the whole experiment an academic exercise.