Than Phu Ying Sirikitiya Jensen (Thai: สิริกิติยา เจนเซน, born March 18, 1985), or Sirikittiya Mai Jensen (Thai: สิริกิตติยา ใหม่ เจนเสน; RTGS: Sirikittiya Mai Chensen), born Mai Jensen (Thai: ใหม่ เจนเซน), is a granddaughter of King Bhumibol Adulyadej of Thailand and a niece of King Vajiralongkorn of Thailand. She is a daughter of Princess Ubolratana Rajakanya (the King's eldest daughter) and her American former husband Peter Ladd Jensen. She is also known by her birth name and nickname as Khun Mai.