A series of poker tournaments held annually in Las Vegas and, since 2005, sponsored by Caesars Entertainment (known as Harrah's Entertainment until 2010). It dates its origins to 1970, when Benny Binion invited seven of the best-known poker players to the Horseshoe Casino for a single tournament, with a set start and stop time, and a winner determined by secret ballot.

The winner of each event receives a World Series of Poker bracelet and a monetary prize based on the number of entrants and buy-in amounts. Over the years, the tournament has grown in both the number of events and in the number of participants. Each year, the WSOP culminates with the $10,000 no-limit hold'em "Main Event," which, since 2004, has attracted entrants numbering in the thousands. The victor receives a multi-million dollar cash prize and a bracelet, which has become the most coveted award a poker player can win. The winner of the World Series of Poker Main Event is considered to be the World Champion of Poker.