Joran Vliegen is a Belgian professional tennis player who specializes in doubles. Vliegen has a career high ATP doubles ranking of World No. 17 achieved on 7 August 2023. He also has a career high singles ranking of World No. 508 achieved on 1 August 2016. Vliegen has claimed 8 ATP tour doubles titles with partner Sander Gillé, including an ATP Masters 1000 title at 2024 Monte-Carlo Masters. He has also won two singles titles on the ITF Men's Circuit.

The Association of Tennis Professionals (ATP) is the governing body of the men's professional tennis circuits – the ATP Tour, the ATP Challenger Tour and the ATP Champions Tour. It was formed in September 1972 by Donald Dell, Jack Kramer, and Cliff Drysdale to protect the interests of professional tennis players, and Drysdale became the first president. Since 1990 the association has organized the ATP Tour, the worldwide tennis tour for men and linked the title of the tour with the organization's name. It is the governing body of men's professional tennis. In 1990 the organization was called the ATP Tour, which was renamed in 2001 as just ATP and the tour being called ATP Tour. In 2009 the name of the tour was changed again and was known as the ATP World Tour, but changed again to the ATP Tour by 2019. It is an evolution of the tour competitions previously known as Grand Prix tennis tournaments and World Championship Tennis (WCT). The ATP's global headquarters are in London. ATP Americas is based in Ponte Vedra Beach, Florida; ATP Europe is headquartered in Monaco; and ATP International, which covers Africa, Asia and Australasia, is based in Sydney, Australia.