Owen A. Gallagher graduated from Boston College High School and Boston College before earning a law degree from Boston University School of Law. He began his career in public service in the Massachusetts House of Representatives and later served in the Massachusetts Senate. Gallagher also held leadership roles in Boston's municipal government and was involved in urban renewal initiatives through the Boston Housing Authority. During World War II, he served in the United States Navy.

Owen A. Gallagher's political career reveals a consistent focus on urban development, blending progressive housing initiatives with a pragmatic approach to regional economic stability. His advocacy for urban renewal and slum clearance programs indicates a forward-thinking stance on urban policy, yet his political maneuvers suggest a calculated effort to balance progressive goals with local industrial interests. Gallagher's wartime service adds a layer of patriotic commitment, yet his electoral setbacks hint at a complex interplay between his policy ideals and political pragmatism.