Kingda Ka is a hydraulically-launched steel roller coaster located at Six Flags Great Adventure in Jackson, New Jersey, United States. Manufactured by Intamin and designed by Werner Stengel, Kingda Ka opened as the tallest and fastest roller coaster in the world on May 21, 2005, surpassing Top Thrill Dragster.

As of early 2026, the title of the tallest roller coaster in the world is held by Kingda Ka at Six Flags Great Adventure in New Jersey, which stands at a staggering 456 feet (139 meters). However, its long-held reign is being challenged by the imminent opening of Falcon's Flight at Six Flags Qiddiya in Saudi Arabia, which is designed to reach a world-record height of over 600 feet. In the United States, a new contender called Tormenta Rampaging Run is debuting at Six Flags Over Texas in 2026, marketed as the tallest "giga dive coaster" in the world at over 300 feet. For those seeking extreme verticality, these "strata coasters" (coasters over 400 feet) remain the gold standard of thrill. It is worth noting that height often correlates with speed; Kingda Ka reaches 128 mph in just 3.5 seconds, providing an experience that is as much about the physical "launch" as it is about the massive vertical tower.