Vimalachatra (Thai: วิมลฉัตร; RTGS: Wimonchat; 27 June 1921 – 5 December 2009), Her Full title : Her Highness Princess Vimalachatra was a Princess of Thailand and member of the Thai royal family, a granddaughter of King Chulalongkorn.

The couple have a son and a daughter; Princess Vimalachatra performs many royal functions and many social duties on behalf of the King and Queen.

She has shown keen interest in public affairs and education of the poor around the country.

She died in the early of 5 December 2009, at Praram 9 Hospital, Bangkok from renal failure.

She died on King Bhumibol Adulyadej's 82nd birthday, before the royal birthday ceremony at the Grand Palace; seven days of Royal funeral were held at Wat Debsirin.