After Missouri voters approved Amendment 2 on Nov. 5, 2024, Missouri became the 39th state to legalize sports betting. After the results of the election were certified on Dec. 5, 2024, sports betting officially became legal in the state.

Voters approved Amendment 2, with 50.05% voting in favor and 49.95% opposing.

While sports betting is now legal in Missouri, the state still has to issue rules and regulations for sports betting to take place. Amendment 2 states that sports betting must be established no later than December 2025, but according to Mike Leara, executive director of the Missouri Gaming Commission, sports betting will likely be launched in the state by late spring or early summer of 2025.

Under Amendment 2, the Missouri Gaming Commission will allow licensed entities to offer sports wagering through online sports wagering platforms to individuals located in the state, at excursion gambling boats, or at any location within each sports district. The amendment provides for license fees and a 10% wagering tax on revenues received to be appropriated for education purposes, including public schools and higher education. It also provides for funding to the Compulsive Gambling Prevention Fund, which includes researching compulsive gambling, implementing treatment and recovery programs, and providing services related to compulsive gambling.

Under the amendment, only individuals 21 years of age or older can participate in sports betting.

Currently, 38 other states and Washington D.C. have legalized and operational sports betting.

New Jersey was the first state where voters approved a sports wagering ballot measure in 2011. After New Jersey modified its restrictions on legalized gambling in 2014, the NCAA, NBA, NFL, NHL, and MLB filed litigation in federal district court. The case, Murphy v. NCAA, went up to the U.S. Supreme Court. On May 14, 2018, the Supreme Court ruled 7-2 that the federal government could not require states to prohibit sports betting, thereby overturning the federal ban on sports betting and allowing states to legalize sports betting.

After New Jersey, five additional states—Arkansas, Colorado, Maryland, Missouri, and South Dakota—legalized sports betting through a ballot measure. The other states that have legalized sports wagering did so through the legislative process.

California was the only other state that had sports betting on the ballot, but voters rejected two measures in 2022—one initiative that would have legalized sports betting at American Indian gaming casinos and licensed racetracks, and one initiative that would have legalized online and legal sports betting.