Dorothea de Schweinitz was born on September 5, 1891 in Nazareth, Pennsylvania, the third child of Bishop Paul de Schweinitz and Mary Catherine Daniel. De Schweinitz attended the Moravian Parochial School and graduated from Smith College in 1912. Descendant of six generations of ministers, she became a volunteer social worker in Bethlehem after graduation. During her career in vocational and employment guidance work, she also pursued post-graduate studies at the Universities of Wisconsin and Chicago and received her MA in Economics from Columbia University in 1929.

It was in New York City that de Schweinitz became interested in the difficulties of low-skilled laborers through her work as placement secretary at the Central Branch of the Y.W.C.A. de Schweinitz spent twenty years in vocational and employment guidance work, developing a Junior Employment Service in the public schools in Philadelphia and in service for the Pennsylvania State Employment Service, as well as working in the research departments of the Wharton School (Penn.) and the U.S. Employment Service in Washington D.C. In 1937, de Schweinitz was appointed as one of the first of three female regional directors for the National Labor Relations Board, in St. Louis. De Schweinitz spent the next twenty years in employer-labor relations and as an industrial relations specialist for the War Production Board in Washington D.C. beginning in 1942.

After her long and successful career, de Schweinitz gave her time in retirement to another pioneer field, historical preservation, in volunteer work in establishing Georgetown as an historic district. She was also very active in the Washington branch of the Smith College Club. De Schweinitz was awarded a Smith College Medal in 1974.

De Schweinitz received a number of grants to support her studies and publications on employment and labor relations, including one from the Wertheim Committee of Harvard University in 1948.

Until her death at the age of 89 on November 15, 1980, de Schweinitz enjoyed writing and publishing small pieces about her experiences and enjoyed visiting friends in the U.S. and abroad. Her informal writings are uniformly cheerful and articulate and demonstrate, as she would say herself, her diffidence and sociability and sense of responsibility to the community.