Hydes is an unincorporated community in both Harford and Baltimore Counties, Maryland. It is located in the Long Green Valley. The United States Postal Service has assigned Hydes the postal code 21082. Saint John the Evangelist church is located in Hydes and is the oldest Roman Catholic Church in Baltimore County. Until 1958, this community was served by the Maryland and Pennsylvania Railroad at milepost 16.8. It is also home to several wineries, including Boordy Vineyards.
Hydes is named for Samuel N Hyde, an agronomist who developed a strain "Egyptian" sweet corn canned by the F. B.Jenkins canning operation of Hyde, MD.