Horvát Mártírok temploma, Catholic church in Udbina, Croatia

Horvát Mártírok temploma is the largest church in Udbina, built in 2005–2010 on the initiative of Bishop Mile Bogović as a national sanctuary for Croatian martyrs. Its cornerstone was cut from the foundations of the 1185 Krbava cathedral and blessed by John Paul II at Trsat in 2003. The altar relief "Slava hrvatskih mučenika" by Kuzma Kovačić, blessed in 2015, is a seven-and-a-half-metre triptych showing the 1493 Krbava battle, Bleiburg, and Vukovar.

Bishop Mile Bogović of Gospić-Senj proposed the church in 2002 to commemorate the 1493 Battle of Krbava Field and all Croatian victims; the Croatian Bishops' Conference backed the idea in 2003, and Archbishop Josip Bozanić suggested the name. The cornerstone, taken from the foundations of the 1185 Krbava cathedral, was blessed by John Paul II at Trsat on 8 June 2003 and laid at Udbina on 9 September 2005. The church was completed and blessed on 11 September 2010 before about 15,000 pilgrims, with Mass led by Cardinal Vinko Puljić.

The church publishes an annual calendar of Croatian martyrs that also lists people with recorded martyrdom who were never formally proclaimed martyrs, their names printed in a different colour. The 2015 edition reproduced photographs and final letters of Croats condemned to death for faith and homeland, saved from oblivion by Anđelko Mijatović and Maja Runje. The church's bulletin is the paper Hrvatska vjernost.

The church is open to visitors and operates for regular religious services under the Roman Catholic Diocese of Gospić-Senj. Visitors should dress appropriately and show respect for ongoing worship activities.

In the church's centre stands a copy of the early medieval baptismal font of Prince Višeslav, found in 1853 in the San Salvador monastery on the Venetian island of Giudecca and probably originally kept in the baptistery at Nin. The cornerstone came from the foundations of the 1185 Krbava cathedral and was blessed by John Paul II at Trsat on 8 June 2003.