Amber Dawn Miller is an American experimental cosmologist born on December 15, 1971, in California, United States. She earned her B.A. in astronomy and physics from the University of California, Berkeley, and her Ph.D. in physics from Princeton University. Miller built a distinguished academic career at the University of Southern California (USC), where she served as a professor of physics and astronomy and later became the dean of the USC Dornsife College of Letters, Arts, and Sciences, overseeing a large multidisciplinary institution with nearly 2,000 faculty and staff. Her work in experimental cosmology has earned her recognition including a National Science Foundation Career Award and fellowship in the American Physical Society.

In September 2024, Miller transitioned from academia to philanthropy, assuming the role of president of the William and Flora Hewlett Foundation (also referred to as the Hewlett Foundation), a prominent organization dedicated to advancing social and environmental causes through grantmaking. As a California native based in Los Angeles, she brings her expertise in science policy and leadership to guide the foundation's initiatives, positioning her at the intersection of science, policy, and global challenges. Throughout her career, Miller has been instrumental in fostering interdisciplinary research, promoting diversity in STEM fields, and influencing educational policies and funding priorities.