- Location: Frederick, MD
- League: Carolina League 1989-2020;
- Affiliation: Baltimore Orioles 1989-2020
- Ballpark: Harry Grove Stadium 1989-2019
The Frederick Keys began play in the Class A Carolina League in 1989 when the Baltimore Orioles relocated their affiliate, the Hagerstown Suns, to Frederick, MD. The club had been an Orioles farm team for its entire existence. The Keys have won league championships in 1990, 2005, 2007 and 2011.
They are named after famous Marylander Francis Scott Key, composer of "The Star Spangled Banner," who was born in Frederick County. However, during the seventh inning stretch, fans listen to the much more entertaining "We're the Frederick Keys" and are asked to shake their keys.