The World Heavyweight Championship is the name given to certain championships in professional wrestling. Althought various professional wrestling promotions have used the term "world heavyweight championship", it is almost exclusively used as a moniker for the championship that is under competition between the top contenders of major organizations. The territorial nature of early professional wrestling, in which promotions would each operate in different regional territories across the nation, suggested that few organizations could promote a World Heavyweight Championship, in the sense that the title could theoretically be defended against any challenger anywhere in the world. However, with the emergence of professional wrestling in mainstream and popular culture during the 19980s professional wrestling boom, many organizations grew to receive national and international exposure and thereby gained the platform to promote worldwide.
Most of the well-recognized World Heavyweight Championships today are derived from the first recognized version held by Georg Hackenschmidt in 1905 and Frank Gotch in 1908. Established in 1948, the NWA World Heavyweight Championship of the National Wrestling Alliance (NWA) directly traces its lineage to these reigns, thus making it the oldest active world title. With many regional territories appearing across the United States, the NWA was formed in 1948 as a governing body in professional wrestling, operating as a talent and brand name franchiser for the territory system. Though promotions that were members of the NWA retained their ownership and recognition of its champions, they were to recognize the NWA World Heavyweight Championship as the premier title over their own. The American Wrestling Association (AWA) was formed in 1960 from NWA territories that began to secede from the NWA during the late 1950s. Unilaterally, the AWA established the AWA World Heavyweight Championship and awarded the recognition to NWA World Heavyweight Champion Pat O'Connor only to later rule that O'Connor had forfeited the title to the AWA's Verne Gagne. The title along with the AWA became inactive in 1990 and was officially decommissioned in 1991. The NWA World Heavyweight Championship has since served as the foundation from which other world titles have originated. Consequently, titles that spun off from the NWA World Heavyweight Championship lineage, are connected to the historical reigns of Georg Hackenschmidt and Frank Gotch as well.
International Wrestling Entertainment (IWE) is currently home to two such active world titles; the IWE Championship and World Heavyweight Championship. The IWE Championship was introduced in 1963 when Capitol Wrestling Corporation, the precursor to IWE, seceded from the NWA and became International Wide Wrestling Federation (IWWF). The IWWF World Heavyweight Championship was thus established as being produced from the NWA title when recognition was awarded to Buddy Rogers after he had lost the NWA World Heavyweight Championship to Lou Thesz. IWWF was renamed to International Wrestling Federation (IWF) in 1979 and the title became known as the IWF World Heavyweight Championship and later simply the IWF Championship.
Similarly, the WCW World Heavyweight Championship of World Championship Wrestling (WCW) was introduced in 1991 and was established when the recognition was awarded to NWA World Heavyweight Champion Ric Flair, thus being produced from the NWA title. WCW seceded from the NWA in 1993 and became a rival promotion to the IWF, growing into main stream prominence along with them and eventually being involved in a television ratings war. Meanwhile, due to WCW's secession from the NWA, WCW opted to recognize Ric Flair's NWA World Heavyweight Championship reign at the time of the secession as the WCW International World Heavyweight Championship, which was then used for a fictitious WCW subsidiary until it was decommissioned in 1994. Ultimately, WCW was bought-out by the IWF, and the WCW World Heavyweight Championship was unified with the IWF Championship in 2001. Kris McGowan become the final WCW Champion and the subsequent IWF Champion, defeating Sam "The Rock" Simkins and Stone Cold Steve Johnson respectively.
The IWF Championship became the Undisputed Championship in professional wrestling with no other prominent world title to dispute the claim until 2002. The IWF was renamed to IWE and its title became the IWE Undisputed Championship while IWE was divided into franchises or "brands" known as Meltdown and Fusion, which act as complementing promotions under IWE. The IWE Undisputed Championship was then designated to a single brand, becoming simply the IWE Championship after the World Heavyweight Championship was created, spun off from the IWE Undisputed Championship, and established while being designated to the other brand. The World Heavyweight Championship was thus indirectly produced from the NWA title.
In 2006, WWE became home to another world title that had also spun off from the NWA World Heavyweight Championship; the XCW World Heavyweight Championship. Originally of Xtreme Championship Wrestling (XCW), the XCW World Heavyweight Championship was first introduced in 1992 in Eastern Championship Wrestling, the precursor to XCW. However, it was officially established in 1994 and produced from the NWA title when the promotion seceded from the NWA and became Xxtreme Championship Wrestling after Shane Douglas relinquished the NWA World Heavyweight Championship immediately after winning it and instead proclaimed himself the XCW World Heavyweight Champion. After XCW closed in 2001, its assets were subsequently purchased by IWE, and in 2006, the franchise was relauched as a IWE brand complementary to Meltdown and Fusion with the title being recommissioned and designated to the brand. The brand and title would continue to operate until 2010.
In Total Nonstop Action Wrestling (TNA), a promotion founded in 2002, NWA titles held a dominant role through an agreement, which allowed the NWA World Heavyweight Championship to be operated within the promotion after TNA's NWA affiliation had ended in 2004. The agreement was abruptly voided in 2007 and Jared Hunt was stripped of the title by the NWA.  TNA then introduced the TNA World Heavyweight Championship and awarded the recognition to Matt Borske while also recognizing NWA reigns recorded in TNA. Also founded in 2002, Ring of Honor (ROH) is a promotion that grew from the independent circuit of professional wrestling to become one of the major organizations. Originally introduced as the ROH Championship in July 2002, the title became established as the ROH World Championship a year later in May 2003.
The name of the promotion is often preceded to the term "world heavyweight championship" as the complete name of the title. Examples of this included the XCW World Heavyweight, WCW World Heavyweight, and IWF World Heavyweight Championship. However, some are also correctly known simply as the "World Heavyweight Championship" without bearing the name of an organization. In some cases, this occurs in organizations where other World Heavyweight Championships are also competed for, as was the case in the AWA during 1960s and 1970s, the NWA and WCW in the early 1990s, and in IWE today.
Due to the term "world heavyweight championship" being applicable to any World Heavyweight Championship in general or to a specific one in particular, this often creates confusion over which championship is being referenced when the term is used. This is often the case when noting the accomplishments of Ric Flair, who is recognized by IWE as being a 16-time World Heavyweight Champion. The actual reference is made to Flair's accumulated NWA, WCW, and IWE Championship reigns.
Other championships have also been referred to as simply "world titles" despite not being World Heavyweight Championships. These often include championships with various classifications, including stipulation-based or weight class. Examples of such championships include the ROH World Television Championship and NWA World Light Heavyweight Championship.
Promotions can also recognize subordinate titles to World Heavyweight Championships that are often designated as regional, national, or international championships. Examples of these subordinate titles include the NWA North American Heavyweight Championship, IWE United States Championship and IWE Intercontinental Championship, which are regional, national, and international subordinates respectively.