Basilika Seckau, Parish church and cultural property in Seckau, Austria.

Basilika Seckau is the abbey and parish church of Seckau in Styria, built of light tan Seckau sandstone. Its neo-Romanesque twin-tower facade, rebuilt 1891–1893, rises 47.5 m and carries a papal tiara and imperial crown. Inside, a three-aisled hall with grey stone columns and pointed arches leads to the high altar, above which a wooden Romanesque crucifixion group hangs on iron chains.

Provost Wernher von Galler began a three-aisled basilica in 1143, and Bishop Hartmann of Brixen consecrated it on 16 September 1164. In 1218 Seckau became a suffragan diocese of Salzburg, making the church a cathedral until the see moved to Graz in 1782. The north tower collapsed on 26 May 1886; both towers and the west facade were rebuilt in 1891–1893 to plans by Pirmin Camani under Friedrich von Schmidt. It was raised to minor basilica in 1930.

The church is still called the "cathedral in the mountains" from its years as seat of the Seckau diocese, 1218 to 1782. The Grace Chapel holds the Seckau grace image, a relief of jade-like stone from around 1200 that legend says Adalram von Waldeck found in a tree; it is probably alabaster carved in a Venetian workshop after the Byzantine Nikopoia. Herbert Boeckl painted his Seckau Apocalypse in the Engelkapelle between 1952 and 1960.

Visiting requires respectful behavior in a religious space, and sturdy shoes are recommended for exploring the interior. Some areas may be accessible only at certain times, so checking opening hours beforehand helps plan your visit.

The Seckau Gnadenbild in the Gnadenkapelle is Austria's oldest grace image, a relief of jade-like stone from around 1200. Legend says the abbey's founder Adalram von Waldeck found it in a tree and built the church on that spot; it is probably an alabaster work from a Venetian workshop after the Byzantine Nikopoia.