The 1999 No Mercy held in the United States was the second No Mercy professional wrestling pay-per-view (PPV) event produced by the World Wrestling Federation (WWF, now WWE). It took place on October 17, 1999, at the Gund Arena in Cleveland, Ohio. While the previous No Mercy event was held exclusively for the United Kingdom and held in May, this event was moved to the United States and established No Mercy as the annual October PPV until 2008.

Nine matches, including three championship matches, took place at the event. In the first, The Fabulous Moolah won the WWF Women's Championship from Ivory to become the oldest champion in professional wrestling history at the time. In the second, Chyna defeated Jeff Jarrett to win the WWF Intercontinental Championship, becoming the first and only female Intercontinental Champion in the promotion's history. Lastly, Triple H defeated Stone Cold Steve Austin to retain the WWF Championship. Also on the card was a tag team ladder match in which The New Brood (Matt Hardy and Jeff Hardy) defeated Edge and Christian. The event also marked the last appearance of Jeff Jarrett in the promotion until 2019.

Reviews for the event were generally positive. Both SLAM! Wrestling and 411mania.com rated the event eight out of ten. The tag team ladder match in particular received very positive reviews from critics.