Jo Matumoto (born February 5, 1971) is a Brazilian former professional baseball player. He is a left-handed pitcher.

Matumoto was born in Brazil and is of Japanese descent. He emerged from relative baseball obscurity, signed by the Toronto Blue Jays in 2007 as an undrafted free agent at the age of 36.^[1] Matumoto's wife had contacted agent Randy Hendricks as she desperately searched for someone in North America to give Matumoto an opportunity.^[2] Matumoto did not speak any English at that time.^[3] He became a free agent at the end of the 2008 season.

While playing baseball in Japan, Matumoto was part of an "industrial league" team in Japanese professional baseball, essentially the Japanese equivalent of the Minor League Baseball circuit.^[4] He was signed by the Nippon Blue Jays^[5]—a team unaffiliated with the Toronto Blue Jays, but founded by a former Toronto Blue Jays farm team player, fellow Brazilian Jose Pett.^[2] Matumoto would play in Japan from 1996 until 2001.^[4]

Matumoto returned to Brazil and has seen action playing for their national baseball team since 1995 and was named the Most Valuable Player (MVP) in the 2005 South American Games when he led Brazil to a victory over Venezuela.^[1][2] He was considered the ace of the national team.^[1][5][6] Matumoto pitches with a three-quarters delivery, throwing in the high 80s with a solid slider. His best pitch was a screwball.^[7][8]