Firebird is a defunct floorless roller coaster located at Six Flags America in Prince George's County, Maryland, United States. Originally designed as a stand-up roller coaster by Swiss manufacturer Bolliger & Mabillard (B&M), the ride first opened as Iron Wolf in 1990 at Six Flags Great America. It debuted as the tallest and fastest stand-up coaster in the world, featuring a height of 100 ft and a maximum speed of 55 mph. Iron Wolf also held the distinction as being the first coaster from B&M, a company that later became one of the industry's leading coaster manufacturers. The stand-up coaster was later relocated to Six Flags America, where it reopened as Apocalypse in 2012.
After the park announced plans to retire the ride at the end of the 2018 season, they released a follow-up announcement two weeks later unveiling Firebird, a conversion from stand-up to floorless utilizing new floorless trains from B&M. The track layout remained unchanged. Firebird debuted in 2019 and operated until the park's permanent closure in 2025.