The Diocese of Nakhon Ratchasima (Dioecesis Nakhonratchasimaensis, ) is a Latin Catholic ecclesiastical jurisdiction located in the north-east of Thailand. It is a suffragan diocese of the Archdiocese of Thare and Nonseng.
The diocese covers an area of 41,148 km<sup>2</sup>, covering 3 provinces of Thailand - Buriram, Chaiyaphum and Nakhon Ratchasima; as of 2023, of the 5.2 million citizens of the three provinces, 5,721 were members of the Catholic Church. It is divided into 28 parishes, having 27 priests altogether.
The diocese was created on March 22, 1965, when the Vicariate Apostolic of Ubon was split. December 18, 1965 the Vicariate Apostolic of Nakhorn-Rajasima was elevated to a diocese.
The cathedral of the diocese is the Our Lady of Lourdes Cathedral (à ¸Âà ¸²à ¸ªà ¸Âà ¸§à ¸´à ¸«à ¸²à ¸£à ¹Âà ¸¡à ¹Âà ¸Âà ¸£à ¸°à ¸Âà ¸£à ¸°à ¸Âà ¸±à ¸Âà ¸©à ¹Âà ¸Âà ¸µà ¹Âà ¹Âà ¸¡à ¸·à ¸Âà ¸Âà ¸¥à ¸¹à ¸£à ¹Âà ¸Â), located in the town Nakhon Ratchasima.
The cathedral can hold over 3,000 people.