Q1

Q1 (meaning Queensland Number One) is a skyscraper located in Surfers Paradise, the tourism hub in Gold Coast, Australia.

At 322.5 metres (1,058 feet), Q1 is the world's tallest all-residential building, when measured to the top of its spire. However, Melbourne's Eureka Tower is taller, and hence the world's tallest, if the buildings are compared on either the height of their roof, or their highest habitable floor.

Q1 overtook the 21st Century Tower in Dubai, United Arab Emirates as the world's tallest residential tower. It is the 20th tallest building in the world when measured to its spire, dwarfing the Gold Coast skyline with the closest buildings to Q1's height being the 220 m (722 ft) North Tower of Circle on Cavill and the under construction 240 m (787 ft) Soul building.

The 297 m (975 ft) Eureka Tower apartment building in Melbourne has also been claimed as the tallest building in Australia, and consequently the tallest residential building in the world, because it has more floors and a significantly higher roof than Q1. However, this building lacks any large spire or mast above the roof. According to the ranking system developed by the Council on Tall Buildings and Urban Habitat, the Eureka Tower qualifies as the taller building in two of the four categories in which heights are ranked, namely Roof Height and Highest Occupied Floor, while Q1 is taller in the other two categories, Pinnacle Height and Architectural Top. For comparison, the Q1 building has its top floor at a height of 235 m (771 ft), some 62 metres (204 ft) lower than Eureka's roof.

Q1 will lose its status as the world's tallest residential building sometime in 2008, when the 395 metre (1,296 ft) 23 Marina in Dubai is completed.