The National Association of Social Workers members database lists social workers by the state in which they are licensed to practice. Member listings provide some educational background and employment.
The National Directory of Online Counselors lists members by state. These are licensed mental health workers who provide therapy over the Internet.
The American Board of Examiners in Clinical Social Work issues a credential, Board Certified Diplomate in Clinical Social Work, to psychotherapists who have an advanced degree and are certified by this not-for-profit.
This commercial registry includes professional profiles. Find a school with a social work program or search for one by keyword.
The state licensing boards list all licensees but many of the online sites provide limited information.