Sebastián Martos Roa (born 20 June 1989) is a Spanish athlete specialising in the 3000 metres steeplechase. He represented his country at the 2013 and 2015 World Championships without qualifying for the final. In addition, he finished fourth at the 2014 European Championships and won the silver medal at the 2013 Summer Universiade. In 2017, he competed in the men's 3000 metres steeplechase at the 2017 World Athletics Championships held in London, United Kingdom.