Online gambling, or illegal Internet gambling, is the act of placing, receiving, transmitting, or participating in bets or wagers through the internet. It includes online casinos, sports betting, and virtual poker.

The United States has enacted a number of federal criminal statutes relating to illegal Internet gambling. These include the Wire Act, the Illegal Gambling Business Act, and the Racketeer Influenced and Corrupt Organizations (RICO) provisions. In addition, the Travel Act imposes a ban on gambling activities conducted within interstate commerce.

This law also prohibits the transportation of gambling devices. For instance, in 1996, a Florida marshal seized $3.2 million from the casino operator Discovery Communications, which accepted advertisements from the Costa Rican operation Tropical Paradise.

Another important law that regulates illegal Internet gambling is the Unlawful Internet Gambling Enforcement Act. While the name is confusing, this act aims to prevent the acceptance of financial instruments from illegal Internet bets.

A related law is the Gambling Devices Transportation Act, also known as the Johnson Act. While the act has been used to seize illegal Internet gambling operations, it has also served as an ad hoc enforcement tool against state laws.

Although there are some debates about the law, the commercial nature of the gambling business seems to satisfy the Commerce Clause. However, due process arguments have been hampered by the presence of an interstate element.

Other relevant laws include the UIGEA, which carries a series of criteria for weeding out low-level gambling cases.