King Power MahaNakhon (Thai: คิง เพาเวอร์ มหานคร), formerly known as MahaNakhon (มหานคร), is a mixed-use skyscraper in the Silom/Sathon central business district of Bangkok, Thailand. It was opened in December 2016. It features the unconventional appearance of a glass curtain walled square tower with a cuboid-surfaced spiral cut into the side of the building. Following transfer of the first residential units in April 2016, at 314.2 metres (1,031 ft) with 77 floors, it was recognized as the tallest building in Thailand on 4 May 2016 by the Council on Tall Buildings and Urban Habitat (CTBUH). Featuring hotel, retail and residences, 200 units of The Ritz-Carlton Residences, Bangkok inside the building are priced between around $US1,100,000 to $US17,000,000, making it one of the most expensive condominiums in Bangkok.

The building was recognised as the tallest building in Thailand until the Magnolias Waterfront Residences at ICONSIAM breaks the record in 2018 with the height of 317 metre.