Humane Society of Southern Maryland and York Pennsylvania
- Lists of volunteer and foster needs, online adoption application, and list of available animals.
- http://www.dogrescue.org/

Compassionatte Friends, The: Southern Maryland Chapter
- An international self-help organization offering friendship and understanding to bereaved parents and siblings.
- http://www.wallacecreations.com/TCF_SOMD/

Southern Maryland Emmaus
- A spiritual renewal program intended to strengthen the local church through the development of Christian disciples and leaders. Features newsletters, events, and contacts.
- http://www.somdemmaus.org/

Women in Harmony
- A women only networking referral organization. Membership and local resources.
- http://www.womeninharmony.org/

Southern MD Singles Social
- Social group for single professionals. News, events, FAQ and members only area.
- http://www.smdsinglessocial.com/

Southern Maryland Astronomical Society
- A non-profit organization focused on support amateur astronomers through programs and services of interest, including observing lessons, meetings, and news.
- http://www.smas.us/

Military Officers Association of America - Southern Maryland Chapter
- Newsletters, meeting schedule and contact details.
- http://www.mdmoaa.org/SouthernMd.htm

Celtic Society of Southern Maryland (CSSM)
- Celebrates the common Celtic heritage of Brittany, England, Ireland, The Isle of Man, Scotland, and Wales through its programs and services, and features an events calendar, including an annual festival held in April.
- http://www.cssm.org/

The Calvert Marine Museum Society
- A public, non-profit, educational, regionally oriented museum dedicated to the collection, preservation, research, and interpretation of the culture and natural history of Southern Maryland.
- http://www.calvertmarinemuseum.org/

Alternatives for Youth and Families
- Community-based care options for emotionally troubled youth, ranging from family counseling and in-home services to crisis shelters, foster care, and residential treatment.
- http://www.alternatives4youth.org/

Access Southern Maryland
- A directory of regional resources for Calvert, Charles, and Saint Mary's counties.
- http://www.access-somd.org/