The 2013 World Baseball Classic (WBC) was an international professional baseball competition, held from March 2 to 19, 2013. This was the third iteration of the WBC, following the two previous tournaments, held in 2006 and 2009.

Unlike the two previous WBCs, which consisted of the same 16 countries, only the 12 countries that won at least one game in the 2009 WBC were guaranteed a berth in the main tournament. The automatic qualifiers were Australia, China, Cuba, Dominican Republic, Italy, Japan, Mexico, the Netherlands, Puerto Rico, South Korea, the United States, and Venezuela. Four qualification brackets were held in late 2012 and respectively won by Canada, Taiwan, Spain, and Brazil, who joined the WBC as the final four teams (the latter two making their WBC debuts).

As in the 2006 tournament, the first round had a round-robin format, which led to South Korea being eliminated on a run difference tiebreaker. Venezuela also failed to advance out of a tough group. The fourth-place teams in each group – Brazil, Australia, Spain, and Mexico – had to participate in the qualifying round in order to return for the 2017 tournament.

The second round was a modified double-elimination format, as in the 2009 tournament, where the modification was that the final game of each bracket was winner-take-all, even if won by the team emerging from the loser's bracket, although that game only affected seeding as two teams advanced from each bracket. The Netherlands improved on its surprising 2009 run by advancing to the semifinal game, as did two-time defending champion Japan. However, Japan was eliminated in the semi-finals, losing to Puerto Rico. In the final game, the Dominican Republic defeated Puerto Rico to become the first WBC champion from the Western Hemisphere, as well as the first team to complete the WBC with an undefeated record, and the only one to do so until Japan also finished with a perfect record in the 2023 WBC. Robinson Canó of the Dominican Republic was named the Most Valuable Player of the tournament.

The preparations for the third World Baseball Classic were complicated by a dispute between the Japanese Professional Baseball Players Association (JPBPA), the union for all Nippon Professional Baseball players, and MLB over revenue sharing. JPBPA demanded a larger share of advertising and merchandise sponsorship revenue for the tournament, a large chunk of which came from Japanese companies. MLB resisted the move in part due to the fact that the World Baseball Classic is a joint production of MLB and the MLB Player's Association, meaning that those two organizations bore the cost of the tournament.

In July 2012, the JPBPA voted unanimously to boycott the 2013 World Baseball Classic. The move was interpreted by some news outlets as a non-final decision, aimed at raising the pressure on MLB. In September 2012, Japanese players agreed to take part after reaching a compromise with tournament organizers on sharing sponsorship and licensing revenue.

The top three teams from each pool of the first round of the 2009 World Baseball Classic automatically qualified.

In the first round, each team played the other three teams in its pool once. Teams were ranked by winning percentage in the first round, with the top two teams in each pool advancing to the second round. There, the teams from Pools A and B (in Pool 1) and the teams from Pools C and D (in Pool 2) competed in a double-elimination format.