Emma Octavia Lundberg, child welfare leader, was born in Västergötland, Sweden on October 8, 1881, to Frans Vilhelm Lundberg and Anna Kajsa Johanson. The family emigrated from Sweden in 1884, and Lundberg spent her childhood in Rockford, Illinois, graduating from Rockford High School in 1901. Two years later Lundberg entered the University of Wisconsin at Madison, earning her B.A. in 1907 and a master's degree in 1908.

From 1908 to 1913, Lundberg worked in several cities studying living-standards and immigrant households, and engaged in family welfare work. Among the organizations that Lundberg worked for were the United States Immigration Commission, the United Charities of Chicago, the Associated Charities in Madison, Wisconsin, and the Associated Charities in Milwaukee. In 1913, she became a deputy at the Wisconsin Industrial Commission and conducted surveys for the state's new minimum wage legislation.

In November 1914, Lundberg moved to Washington, D.C. to serve as the first Director of the Social Services Division of the United States Children's Bureau, a young agency established two years earlier. Shortly thereafter Katherine F. Lenroot, Lundberg's assistant at the Wisconsin Industrial Commission, also joined the Bureau and became the Assistant Director of the division. Lundberg directed studies on illegitimacy, juvenile delinquency, the care of children described then as mentally deficient and state child welfare laws. She wrote numerous articles and reports, and many of her studies were published as Children's Bureau publications. Her publications from this period include Illegitimacy as a Child Welfare Problem (1920, 1922), Juvenile Courts at Work (1925), both co-authored with Lenroot, along with Children Deprived of Parental Care (1926), and Public Aid to Mothers with Dependent Children (1926).

In 1925, Lundberg resigned from the Children's Bureau to join the Child Welfare League of America (CWLA), a coalition of child welfare organizations that was established in New York in 1920. Lundberg first served as the Director of the Department of Institutional Care, and later as the Director of Studies and Surveys. Besides her book Child Dependency in the United States (1933), she frequently authored articles in the CWLA's publications. In the early years of the Great Depression, based on her two decades of experience in social work, Lundberg was appointed the Director of Research and Statistics at the New York Temporary Emergency Relief Administration under Governor Franklin Delano Roosevelt. She also worked as a consultant for other public agencies and conducted research for Philadelphia and Florida.

Lundberg rejoined the Children's Bureau in 1935 at the request of Katherine Lenroot who had been promoted to the third Chief of the Bureau in December 1934. From 1935 to 1942 Lundberg served as the Assistant Director of the Child Welfare Division, and from 1942 to 1945 as consultant in social services for children. The responsibilities of the Children's Bureau expanded significantly during the New Deal, and Lundberg's contributions included laying the foundation of children welfare provisions under the Social Security Act of 1937. She was also the Assistant Secretary to the 1940 White House Conference on Children in a Democracy.

In 1945, Lundberg retired from Washington due to ill health. She continued to write nevertheless, and published Unto the Least of These: Social Services for Children in 1947. After Lenroot's retirement in 1951 and until Lundberg's death in 1954, Lundberg and Lenroot shared a home in Hartsdale, New York.

Emma O. Lundberg died on November 17, 1954; she was 73 years old.