Thomas Nantha (3 October 1909 – 7 April 1984) was a Laotian Roman Catholic prelate.
He was titular bishop of Succuba from 1974 until his death and vicar apostolic of Vientiane from 1975 to 1984.
He was consecrated by pope Paul VI on 30 June 1974 in St. Peter's Basilica.
He was also apostolic administrator of Luang Prabang from 1975 to 1984.
He was also a presiding manager of the Episcopal Conference of Laos and Cambodia from 1979 to 1984.