The Diocese of Osma-Soria (Latin: Oxomen(sis)–Sorian(a)) is a Latin Church ecclesiastical territory or diocese of the Catholic Church in northern Spain.

It is a suffragan diocese in the ecclesiastical province of the metropolitan Archdiocese of Burgos.

[1][2] Its cathedral episcopal see is Catedral de Santa María de la Asunción, dedicated to the Assumption of Mary, in El Burgo de Osma.

It also has a co-cathedral, Concatedral de San Pedro, dedicated to St. Peter, in Soria, and a minor basilica: Basílica de Nuestra Señora de los Miagros Miagros, in Ágreda, Soria, Castile and León, Spain.

As per 2014, it pastorally served 80,000 Catholics (85.8% of 93,291 total) on 10,287 km2 in 542 parishes and 19 missions with 128 priests (103 diocesan, 25 religious), 212 lay religious (38 brothers, 174 sisters) and 1 seminarian.