Wat Worachettharam (, ) is an ancient temple in Phra Nakhon Si Ayutthaya province, central Thailand, located in inner city of Ayutthaya, also known as Ayutthaya Island, hence the other name Wat Worachet Nai Ko (à ¸§à ¸±à ¸Âà ¸§à ¸£à ¹Âà ¸Âà ¸©à ¸Âà ¹Âà ¹Âà ¸Âà ¹Âà ¸Âà ¸²à ¸°, "Worachet Temple on the island").
Originally it was named Wat Chao Chet (à ¸§à ¸±à ¸Âà ¹Âà ¸Âà ¹Âà ¸²à ¹Âà ¸Âà ¸©à ¸Âà ¹Â, "temple of the royal elder brother") later it was renamed by King Ekathotsarot to Wat Worachettharam, which means "temple of sublime elder brother".