Mom Rajawongse Thanadsri Svasti (Thai: หม่อมราชวงศ์ถนัดศรี สวัสดิวัตน์, RTGS: Thanatsi Sawatdiwat, 28 May 1927 – 27 August 2019) was a Thai writer, singer, broadcaster and actor, best known as a culinary expert and for his food writing, especially the "Shell Chuan Chim" (เชลล์ชวนชิม) food guide.