Ampon Tangnoppakul (Thai: ???? ?????????; RTGS: Amphon Tangnopphakun; 1 January 1948 – 8 May 2012), commonly known in Thai as Ah Kong (????; meaning 'grandpa') or in English as Uncle SMS, was a Thai national accused of sending four Short Message Service (SMS) messages from his cell phones to Somkiat Khrongwatthanasuk, secretary of then Prime Minister Abhisit Vejjajiva.
The messages were deemed offensive to the King and Queen of Thailand, as proscribed by section 112 of the Criminal Code of Thailand and the law on computer-related offences.
Having been found guilty of four charges in November 2011, he was sentenced by the Criminal Court to four consecutive five-year terms, for a total of twenty years in prison.