Parkville is located at 39°22?59?N 76°33?0?W / 39.38306°N 76.55°W / 39.38306; -76.55 (39.383039, -76.550065).
According to the United States Census Bureau, the CDP has a total area of 4.2 square miles (11.0 km²), all of it land. Census Bureau maps designate the borders as I-695 from Loch Raven Blvd. to Putty Hill Ave. to the North, Putty Hill Ave. from I-695 to Fowler Ave., Fowler Ave. from Putty Hill Ave. to Hiss Ave., Hiss Ave. from Fowler Ave. to Glen Road to the East, the Baltimore City/Baltimore County border from near Glen Road to Loch Raven Blvd. to the South, and Loch Raven Blvd. from the city line to I-695 to the West.