Mezquita de Osman Saj

The Osman Shah Mosque is a sixteenth-century Ottoman mosque in the city of Trikala, Greece, known in Ottoman times as Tırhala. It is also called the Lead Mosque, from the Turkish kurşun camii, rendered in Greek as Koursoum Tzami. Built in the Ottoman architectural tradition, it is listed as an official archaeological site. It takes its name from its founder, Osman Shah.

The mosque was endowed by Osman Shah, also known as Kara Osman Pasha. He was a son of one of the daughters of Sultan Selim I and served for a long period as governor of the sanjak of Tırhala, based in Trikala. The exact date of construction is uncertain; the available material points to the mid-sixteenth century, most probably the late 1550s.

Osman Shah also established several charitable institutions linked to the mosque, including a madrasa, a poorhouse and a caravanserai. After his death in 1567/8 he was buried in a tomb in the mosque's southern courtyard. When Evliya Çelebi visited about a century later, it was the main mosque of the town.