Dubuque Arboretum and Botanical Gardens, also called Marshall Park, is a fifty-six-acre public garden and arboretum in Dubuque, Iowa, established in 1980. Open daily from dawn to dusk without admission fees, it features Japanese and English gardens, flower displays, tree collections, a veterans memorial, and a visitor center. In 2025, it introduced a thirty-year master plan with proposals for a three thousand five hundred-seat amphitheater and a canopy walkway, reflecting continued development of the site as a major horticultural and community space.