Protestant Great Church of Debrecen, Reformed church in Debrecen, Hungary.

The Reformed Great Church stands between Kossuth Square and Kálvin Square, its two 61-metre towers joined by a facade gallery added in 1823–24 to Károly Rábl's plans. The main nave is 55 m long and nearly 15 m wide, the transept 38 m by 14 m, and the white-walled interior reaches 21 m in height, holding about 3,000 seats.

Construction of the neoclassical building began in 1805 under architect Mihály Péchy, following the destruction of earlier churches by fires in 1564 and 1802. The new structure was built to provide a permanent home for the reformed congregation after these losses.

The church's nickname for Debrecen, "the Calvinist Rome", comes from this building's role as the symbol of the Hungarian Reformed Church. Inside, the armchair Lajos Kossuth used when the Hungarian Declaration of Independence was proclaimed here on 14 April 1849 can still be seen. The Rákóczi bell hangs in the western tower.

The older organ, built by Jakob Deutschmann in 1838, stands behind the pulpit; the 1981 electronic organ with resonance pipes sits above the main entrance in the southern part. The western tower, reached from inside, gives a panorama over Debrecen. The interior holds about 3,000 seats, so allow time to cross it.

Lajos Kossuth declared Hungarian independence within these walls on April 14, 1848, and the chair he sat in during that moment remains on display in the building. This piece of furniture is a physical link to one of the nation's most important turning points.