Harney (Monocacyville as late as 1892) is an unincorporated community in Carroll County, Maryland, United States.

Harney is located near the head of the Monocacy River to the northwest and is the site of the following crossroads: east/west Conover Road (named for a family who owned a defunct farm on the east of the town) and north/south Harney Road.

Communities near Harney are Longville to the south,[4] Emmitsburg (southwest) and in Pennsylvania, Natural Dam (west), Mt.

(Occasional deliveries to Harney from the store at the Natural Dam mill to the west provided mail from the Fairplay, Pennsylvania, route.)

[74] ** The Reaser Hose camp and adjoining[75] "Good Samaritan Masonic Camp"[36] were northwest of Harney at S. D. Reck's woods[76]/dam on Rock Creek near the Monocacy[77] where there was a 1935 grove, clubhouse, and baseball field.