Professional wrestling, often referred to as pro wrestling, or simply, wrestling, is a form of athletic theater centered around mock combat with the premise that its performers are competitive fighters.

Professional wrestling gradually developed from competitive catch wrestling in the late 19th century, when wrestlers and promoters began staging fake matches to exhibit more excitement and draw larger audiences. Over the course of the 20th century, it was increasingly known that professional wrestling was scripted, but the appeal for fans shifted from its competitive element to the entertainment value; wrestlers subsequently responded by incorporating drama, gimmickry, and outlandish stunts into their performances, while maintaining the pretense of engaging in a competitive sport. Eventually, the term "professional wrestling" was legally defined as a non-sport by various government regulators because legitimate wrestling was effectively confined to amateur enthusiasts.

Professional wrestlers perform as characters and usually maintain what is known in the industry as a gimmick—the persona, style, and traits conveyed by their distinctive attires, ring names, entrance music, and other distinguishable attributes and characteristics. Matches are the primary vehicle for advancing storylines, which typically center on feuds between heroic "faces" (also called babyfaces) and villainous "heels", although more modern wrestling has increasingly featured morally ambiguous "tweeners". A wrestling ring, akin to a boxing ring, serves as the main stage; additional scenes may be recorded for television in backstage areas of the venue, in a format similar to reality television. Performers generally integrate authentic wrestling techniques and fighting styles with choreography, stunts, improvisation, and dramatic conventions designed to maximize audience engagement. Unlike in other forms of entertainment, wrestlers usually remain in character even when they are not performing; this dedication to presenting scripted events as authentic is known as kayfabe.

Professional wrestling is performed around the world through various promotions, which are roughly analogous to production companies or sports leagues. Promotions vary considerably in size, scope, and creative approach, ranging from local shows on the independent circuit to internationally broadcast events at major arenas. The largest and most influential promotions are in the United States, Mexico, Japan, and Europe (particularly the United Kingdom, France, and Germany/Austria), which have each developed distinct styles, traditions, and subgenres within professional wrestling. Many professional wrestlers also perform as freelancers and make appearances for different promotions.

Professional wrestling has developed its own culture and community, including a unique glossary of terms. It has achieved mainstream success and influence within popular culture; many wrestling phrases, tropes, and concepts are now referenced in everyday language and in film, television, music, and video games. Numerous professional wrestlers have become national or international sports icons with recognition by the wider public, with some finding further fame and success through other endeavours such as acting and music.

In the United States, authentic wrestling is generally practiced in an amateur context. There is no professional league for competitive wrestling in most Western countries, due to a lack of popularity; one case in point is Real Pro Wrestling, an American professional freestyle wrestling league that dissolved in 2007 after just two seasons.

In numerous American states, professional wrestling is legally defined as a non-sport. For instance, the New York athletic commission defines professional wrestling as:

Professional wrestling means an activity in which participants struggle hand-in-hand primarily for the purpose of providing entertainment to spectators and which does not comprise a bona fide athletic contest or competition. Professional wrestling is not a combative sport. Wrestling constituting bona fide athletic contests and competitions, which may be professional or amateur combative sport, shall not be deemed professional wrestling under this Part. Professional wrestling as used in this Part shall not depend on whether the individual wrestlers are paid or have been paid for their performance in a professional wrestling exhibition. All engagements of professional wrestling shall be referred to as exhibitions, and not as matches.