WWE No Mercy, also known as NXT No Mercy since 2023, is a professional wrestling event produced by WWE, a professional wrestling promotion based in Connecticut. The first No Mercy was held on May 16, 1999, in Manchester, England, and was the only No Mercy event produced in the United Kingdom. A second No Mercy was then held in October that year in Cleveland, Ohio, United States. Beginning with this second event, No Mercy became the annual October pay-per-view (PPV) until 2008. The event was then discontinued and replaced by Hell in a Cell in 2009. After eight years, No Mercy was reinstated in October 2016. However, No Mercy was again discontinued after the September 2017 event, as WWE reduced the amount of yearly PPVs held after they had ended the production of brand-exclusive PPVs following WrestleMania 34 in 2018. In 2023, WWE again revived the event, this time for its developmental brand, NXT, in September.