Callahan Walsh was born on December 6, 1984, in Falls Church, Virginia, the third child of John and Revé Walsh. His eldest brother, Adam, was abducted and murdered in 1981, three years before Callahan was born. The tragedy defined his family’s public crime-fighting mission and shaped his career path. Walsh attended The Harvey School and, later, Stetson University, where he graduated with a Bachelor of Science in Business Administration and Management.

After graduating, he worked in production, starting at Silver Spring Studios. He later joined Walsh Productions, where he worked as a producer on America’s Most Wanted and helped to create The Hunt with John Walsh on CNN. In 2014, he transitioned to the National Center for Missing & Exploited Children, where he now serves as executive director of the Florida Regional Office. 

Callahan Walsh transitioned into TV hosting in 2019 as co-host of In Pursuit with John Walsh on Investigation Discovery. Then, in 2024, he joined his father as co-host of the revived America’s Most Wanted on Fox. In addition to his television work, Callahan regularly appears on Good Morning America, CNN, NBC, ABC, and HLN to raise awareness of NCMEC’s programmes and missing persons cases.