Radomyos Matjiur (born April 2 1988 in Bangkok) is a Thai swimmer who won a gold medal at the 2013 Southeast Asian Games in the 100 m breaststroke. He currently holds the Thai records in swimming in the 100 m breaststroke, 100 m individual medley, 200 m individual medley and 4×50 m freestyle relay. Matjiur also won the 200 m breaststroke final at the Southeast Asian Games in Singapore. He competes in the 100 m breaststroke at the 2016 Summer Olympics in Rio de Janeiro.