Khun Ying Jamsai Silpa-archa (Thai: แจ่มใส ศิลปอาชา, RTGS: Chaemsai Sinlapa-a-cha, IPA: [t͡ɕɛ̀m.sǎj sǐn.lá.pà.ʔaː.t͡ɕʰaː]; born 20 April 1934), née Lekhawat (Thai: เลขวัต, IPA: [leː.kʰà.wát]), is the widow of Banharn Silpa-archa, the 21st Prime Minister of Thailand and Thai Nation Party Leader. They have three children: one son, Varawut (married to Suwanna Raiwin), and two daughters, Kanchana and Parichat.

Jamsai graduated from Phadungsil School in 1944 and graduated from Sanguan Ying School in 1947. She was a founder of Banharn-Jamsai Silpa-archa Foundation to provide educational opportunities to students in Suphanburi province.^[1]

• Order of the White Elephant Benchamaphon Chang Phueak
• Order of the Crown of Thailand Tritaphon Mongkut Thai
• Order of the Crown of Thailand Prathamaphon Mongkut Thai
• Order of Chula Chom Klao Chatutot Chunlachomklao
• Order of the White Elephant Prathamaphon Chang Phueak
• Order of the Crown of Thailand Maha Wachira Mongkut
• Order of the White Elephant Maha Paramaphon Chang Phueak^[2]
• Order of the Direkgunabhorn Pathama Direkkhunaphon^[3]
• Order of Chula Chom Klao Tatiya Chunlachomklao^[4]

• Banharn Silpa-archa
• Banharn-Jamsai Tower