Jonathan Reid Cornelius
- Bats Right, Throws Right
- Height 6' 0", Weight 200 lb.
- High School Thomasville (AL) High School
- Debut April 29, 1995
- Final Game September 30, 2000
- Born June 2, 1970 in Thomasville, AL USA
Reid Cornelius was originally an 11th round pick for the Montreal Expos in the 1988 amateur draft out of high school. Cornelius signed for $200,000 but got in one last appearance as an amateur, helping the US win the 1988 World Junior Championship, before starting his pro career. He was identified by Baseball America as the top pitching prospect in Alabama in their 1988 draft preview, and as the 21st best Major League prospect in 1991.
In 2003, he was named pitching coach of the Carolina Mudcats, then held the same position with the Jupiter Hammerheads from 2004 to 2008. In 2009, he moved up to the Jacksonville Suns and in 2010 was appointed bullpen coach of the Florida Marlins, a position he kept when the team became the Miami Marlins in 2012. He stayed with the Marlins through 2016. He then became pitching coach of the Gwinnett Braves in 2017.