CASA of Harford County
- Volunteer organization that is committed to serving the needs of abused and neglected children who are involved in the judicial system. News and volunteer and contact information.
- http://www.casaofharfordcounty.org/

MDGenWeb: Harford County
- Affiliated with the MDGenWeb and USGenWeb projects this site provides resources for history and genealogy research.
- http://www.rootsweb.com/~mdharfor/

Wikipedia - Harford County, Maryland
- Free encyclopedia. History, government, geography, demographics, cities and towns.
- http://en.wikipedia.org/wiki/Harford_County%2C_Maryland

Harford Habitat for Humanity
- A driving force in eliminating substandard housing in Maryland by creating decent, affordable housing with partner families. Includes upcoming builds, volunteer and donation opportunities, and how to apply.
- http://www.harfordhabitat.org/

Humane Society of Harford County
- Includes photos of animals available for adoption, donation information, and volunteer opportunities.
- http://www.harfordshelter.org/

Home Partnership, Inc.
- A not-for-profit agency dedicated to helping residents of Harford County, Maryland, achieve home ownership.
- http://www.homepartnershipinc.org/

Harford County Astronomical Society
- Stargazing outings, discussion groups, and invited speakers.
- http://www.harfordastro.org/

Harford Bird Club
- Birding club with events, guest speakers, field trips, online newsletter, descriptions of local common species, rare bird alerts, and checklist of all species ever recorded in Harford County.
- http://www.harfordbirdclub.org/

Harford County (Maryland) Genealogical Society
- Preserving and disseminating information on family history and genealogy. Newsletters from 1997 and 1998.
- http://www.rtis.com/reg/md/org/hcgs/default.htm