He is the science correspondent for PBS News Hour, a producer, writer, director, and correspondent for the PBS documentary series NOVA and FRONTLINE, CNN's aviation analyst, and the creator, host and executive producer of the PBS series Resolve to Solve with Miles O'Brien. He is also the founder and president of MOBIAS Media, Inc., an independent production company that produces award-winning documentaries and science programming for public television and other clients.

Over the course of his career, O'Brien has covered many of the defining science and technology stories of our time—from space exploration, aviation safety, and nuclear power to climate change, pandemics, and emerging medical technologies. His reporting has taken him from the depths of the ocean to Antarctica, the Arctic, and the frontiers of space, with a particular focus on explaining complex scientific issues through compelling human stories.

Before joining PBS, O'Brien spent nearly seventeen years as a correspondent and anchor for CNN, where he served as the network's science, technology, environment, and aerospace correspondent.

He anchored several programs, including American Morning, and became widely recognized for his coverage of NASA and the U.S. space program. In 2003, he led CNN's critically acclaimed sixteen-hour live coverage of the Space Shuttle Columbia disaster. He later served for a decade on the NASA Advisory Council, providing strategic guidance to the NASA Administrator.

As a filmmaker, O'Brien has produced, written, and directed numerous documentaries for NOVA and FRONTLINE, including Mind of a Rampage Killer, Manhunt Boston Bombers, Why Planes Vanish, Nuclear Meltdown Disaster, The Nuclear Option, Inside the Megafire, The Great Electric Airplane Race, and the FRONTLINE documentary Coronavirus Pandemic. His reporting for PBS News Hour has earned widespread recognition for its depth, clarity, and commitment to evidence-based journalism.

His newest project, Resolve to Solve with Miles O'Brien, reflects a philosophy that has shaped his reporting throughout his career: while journalism must honestly confront society's greatest challenges, it should also examine credible solutions and the people working to create them. The series explores innovations in climate, energy, conservation, neuroscience, medicine, and technology through the scientists, engineers, and communities leading those efforts.

O'Brien has received numerous honors for his work, including six Emmy Awards, a Peabody Award, and a duPont-Columbia Award.

In 2014, while on assignment, a heavy equipment case struck his left arm, leading to a rare medical complication that required an above-the-elbow amputation. He has since become an advocate for people living with disabilities while continuing to report around the world. Since the accident, he has completed two marathons, a half Ironman, numerous ultradistance cycling events, and returned to flying airplanes.

Born in Detroit and raised in Grosse Pointe Farms, Michigan, O'Brien studied history at Georgetown University. He is an accomplished pilot and continues to cover aviation and aerospace as one of the nation's most respected broadcast analysts.