- Location: Hagerstown, MD
- League: Carolina League 1981-1988; Eastern League 1989-1992; South Atlantic League 1993-present
- Affiliation: Co-op 1981; Baltimore Orioles 1982-1992; Toronto Blue Jays 1993-2000; San Francisco Giants 2001-2004; New York Mets 2005-2006; Washington Nationals, 2007-present
- Ballpark: Municipal Stadium
Three minor league clubs have shared the name "Hagerstown Suns":
In 1981, the Suns began play in the Class A Carolina League as an expansion team based in Hagerstown, MD. It was the league's second expansion in four years, as it had added franchises in Alexandria, VA and Kinston, NC in 1978. The city of Rocky Mount, NC was granted an expansion franchise at the same time as Hagerstown, bringing the league to 8 teams. The club was a co-op team its first year with the Baltimore Orioles supplying the most players, with help from the Minnesota Twins. In 1982 the team became an affiliate of the Orioles. After the 1988 season, the team was relocated to Frederick, MD where they became the Frederick Keys.
After moving their Carolina League team from Hagerstown, the Orioles relocated their Class AA Eastern League farm team from Williamsport, PA to Hagerstown. The new club adopted the former team's name, the Suns. They remained an Orioles affiliate and stayed in Hagerstown until they moved to Bowie, MD and became the Bowie Baysox after the 1992 season.
South Atlantic League
Shortly after the Suns relocated to Bowie, a third Suns franchise was formed in the Class A South Atlantic League. The club was a Toronto Blue Jays affiliate from 1993 to 2000, and was a San Francisco Giants farm club for the next four seasons. In 2005, the Suns became an affiliate of the New York Mets, and after the 2006 season, they switched their affiliation to the Washington Nationals.
- On June 19th, 2005, pitcher Gaby Hernandez threw a 1-0 no-hitter against the West Virginia Power at Municipal Stadium.