Chetthathirat (Thai: เชษฐาธิราช, Jeṣaṭhādhirāja) or Borommaracha II (บรมราชาที่ ๒; c. 1613 – 1629) was the eldest son of King Song Tham and older brother of Athittayawong and Phra Sisin or Phra Phanpi Sisin (Thai: พระพันปีศรีศิลป์), all three of the House of Sukhothai. In childhood he was known as Chetthakuman (พระเชษฐากุมาร), meaning 'Chettha the Infant', or simply Chettha.