General Kiangsak Chamanan (17 December 1917 - 23 December 2003) was fifteenth prime minister of Thailand. He served twice, from 11 November 1977 until 21 December 1978 and from 12 May 1979 until 3 March 1980. His parents were Mr Jam and Mrs Jua Chamanan. He married Lady Wirat Chamanan. His old name was "Somchit" and after that changed to Kiangsak to followed Field Marshal Peak Piboonsongkram's law that the man had to have a name that showed hardenness. He began to study in Primary at Samudsakorn Wittayalai school in Samudsakorn province, Patomkongka school in Bangkok. After that he got into study in a military academy.