Sex clubs are clubs where people can have sexual intercourse with one another in public areas. The term can also be used more generally to refer to establishments such as a gay bathhouse where sexual activity often takes place in private rooms. Larger establishments may also include the facilities of an ordinary nightclub such as a bar and a dance floor.

Sex clubs differ from brothels in that, while sex club customers pay a fee to enter the club, they have sex with other customers rather than with staff of the establishment. Some sex clubs cater exclusively to male/female couples, others to gay men or lesbians. Some clubs do not make any restrictions on the sexuality of their clients.

Typical sex clubs also differ from gay bathhouses in that they do not have private rooms, and all sexual activity must take place in the open. In an effort to curb the spread of sexually transmitted infections, some jurisdictions have banned bathhouses, with their private rooms, while allowing sex clubs, where sexual activity can be monitored to ensure that safe sex guidelines are being followed.

Most U.S. sex clubs do not serve alcohol, but some allow customers to bring their own. Some sex clubs have formal membership and requirements that can include membership fees, showing proof of identity, attending a formal orientation, providing STD test results or showing that one is part of a stable, long term relationship and is attending with that partner. Clubs with such requirements tend to cater to the swinging subculture. Other clubs are open to any person willing to pay an admission fee.

A similar type of club is a masturbation club in which members, either single-gender or mixed, masturbate together in public or private rooms. Sexual intercourse is generally prohibited in such clubs. See also safe sex party.

There is also a very large and growing group of private sex clubs across the U.S. and around the world that do not operate in a specified location. These organizations focus on private parties in homes or rented facilities and make use of the Internet to build their membership. There is usually a small door fee and most are invitation-only.

Swingers clubs tend to be On-Premise Clubs where people pay an entrance fee to meet other couples and have sex. Many couples in the lifestyle will try swingers clubs to see if this is truly what they are looking for. Swingers will also try Off-Premise Clubs which tend to be more meet n greet oriented and sexual activity usually is not permitted.