This is a list of tallest Orthodox church buildings in the world, all those higher than 70 metres.
Traditionally, an Orthodox church building is crowned by one or several domes with Orthodox crosses on the top of each. The overall height of the temple is measured by the highest point of the cross above the main temple.
Eastern Orthodoxy, otherwise known as Eastern Orthodox Christianity or Byzantine Christianity, is one of the three main branches of Chalcedonian Christianity, alongside Catholicism and Protestantism. Like the Pentarchy of the first millennium, the mainstream (or "canonical") Eastern Orthodox Church is organised into autocephalous churches independent from each other. In the 21st century, the number of mainstream autocephalous churches is seventeen; there also exist autocephalous churches unrecognized by those mainstream ones. Autocephalous churches choose their own primate. Autocephalous churches can have jurisdiction (authority) over other churches, some of which have the status of "autonomous" which means they have more autonomy than simple eparchies.
Many of these jurisdictions correspond to the territories of one or more modern states; the Patriarchate of Moscow, for example, corresponds to Russia and some of the other post-Soviet states. They can also include metropolises, bishoprics, parishes, monasteries, or outlying metochia corresponding to diasporas that can also be located outside the country where the primate resides (e.g., the case of the Ecumenical Patriarchate of Constantinople whose canonical territory is located partly in northern Greece and the east); sometimes they overlap (the case of Moldova where the jurisdictions of the patriarchs of Bucharest and of Moscow overlap).
The National Cathedral (Romanian: Catedrala Națională), also known as the People's Salvation Cathedral (Romanian: Catedrala Mântuirii Neamului), is an Eastern Orthodox cathedral in Bucharest, Romania, built to serve as the patriarchal cathedral of the Romanian Orthodox Church. It is located in central Bucharest on Spirea's Hill (Arsenal Square), facing the Palace of Parliament. At 127 metres (417 ft) tall, the cathedral occupies a dominant position in Bucharest's cityscape, being visible from all approaches to the city.
It is the tallest and largest Eastern Orthodox church building by volume, and area, in the world. The People's Salvation Cathedral will have the largest collection of church mosaics (interior decoration) in the world when it is completed, having about 25,000 square meters. Also the People's Salvation Cathedral has the world's largest Orthodox iconostasis (23.8 meters long and 17.1 meters high) and the world's largest free-swinging church bell.