Few have made such a significant impact on the Earth and space science community as Dr. Carol A. Finn through her groundbreaking application of geophysics to support communities, her remarkable record of volunteer leadership at AGU, and her incredible strength as a mentor and role model. She has made lasting contributions toward societal impact, service, scientific leadership, and mentoring that exemplify AGU’s values and express her dedication to the community of Earth and space sciences beyond her own research, a hallmark of the Ambassador Award. Dr. Finn has brought sustained, thoughtful scientific leadership that has measurably transformed organizations and communities. Her pioneering and innovative use of geophysics in support of hazards and natural resource studies has far-reaching impact , bridging scientific and societal contributions. Working on all seven continents, Carol has forged diverse global partnerships to tackle important scientific and societal problems in geophysics and geology, linking basic and applied science with users. Hundreds of thousands who live in the shadow of Pacific rim volcanoes are now safer thanks to automated lahar early-warning systems based on her innovative geophysical imaging of invisible alteration zones that can trigger volcanic mudflows. Through decades of service, Carol stands out for her contributions to the scientific community, including roles as AGU General Secretary (2008–2010) and President (2013–2014). Far beyond a normal “volunteer” role, her extraordinary long-term service made a lasting imprint on AGU as the organization grew into the internationally recognized society that it is today. Her forward-looking leadership supported the development of AGU’s Thriving Earth Exchange (TEX) that enables AGU members to contribute to important societal problems through partnership with community leaders, a program that has now supported more than 350 projects in over 13 countries. For decades, Carol has inspired early-career and female scientists to follow scientific career pathways while striving for positive change through service. Today, next-generation leaders regularly serve on all AGU committees, a testament to her leadership in initiating the trailblazing practice of appointing early-career members to the Board during her service as AGU President. Throughout her remarkable career, she has made outstanding contributions toward societal impact, service, scientific leadership, and promotion of early-career scientists, all tightly aligned with AGU values. Excellence, integrity, respect, diversity, collaboration, science, and global partnerships define her career. For these sustained scientific contributions and transformational service and leadership, Carol Finn is a valued ambassador for the Earth and space science community. —Robin Bell, Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York —Burke Minsley,USGS, Denver, Colorado