Jesús Fernando Martínez Álvarez (born October 10, 1988) is a Dominican former professional baseball outfielder. Martínez signed with the New York Mets in 2005, and made his Major League Baseball (MLB) debut in 2009. He also played in MLB for the Houston Astros. He bats left-handed and throws right-handed. He was one of 14 players suspended for taking part in the Biogenesis baseball scandal. He played for Team Spain in the 2019 European Baseball Championship. He then played for the team at the Africa/Europe 2020 Olympic Qualification tournament, in Italy in September 2019.