Prince Sommatiwongse Varodaya, The Prince of Nakhon Si Thammarat (; ) was the Prince of Siam (later Thailand). He was a member of the Siamese royal family and a son of King Chulalongkorn Rama V of Siam.
His mother was Queen Savang Vadhana, a daughter of King Mongkut (thus his father's half-sister) and Princess Piyamavadi
Prince Sommatiwongse Varodaya died on 17 June 1899 at the age 17.