The Episcopal Conference of Thailand is composed of 2 ecclesiastical provinces, each headed by an archbishop, and 9 suffragan dioceses.

Episcopal Conference of Thailand

Ecclesiastical Province of Bangkok

• Archdiocese of Bangkok
  • Diocese of Chanthaburi
  • Diocese of Chiang Mai
  • Diocese of Chiang Rai
  • Diocese of Nakhon Sawan
  • Diocese of Ratchaburi
  • Diocese of Surat Thani

Ecclesiastical Province of Thare and Nonseng

• Archdiocese of Thare and Nonseng
  • Diocese of Nakhon Ratchasima
  • Diocese of Ubon Ratchathani
  • Diocese of Udon Thani