Born in Lewiston, Maine, on May 27, 1956, Cynthia McFadden attended Bowdoin College, graduating summa cum laude and Phi Beta Kappa in 1978. She then earned a Juris Doctor from Columbia Law School in 1984. Her broadcasting career began with the newly launched Courtroom Television Network in 1991, where she anchored live coverage of more than 200 trials, including the Menendez brothers and Rodney King cases.

ABC News hired her in 1994 as a legal correspondent, and over the following decade, she reported on cases from O.J. Simpson to Martha Stewart. She also co-anchored Primetime from 2004 and made television history as the legal editor and narrator of In the Jury Room — the first program to broadcast actual jury deliberations in a death penalty case. She was later named the co-anchor of Nightline in 2005, becoming the first female journalist to anchor the program.

Cynthia McFadden co-anchored Nightline for nine years before leaving ABC for NBC News in March 2014. There, she turned her focus to investigative journalism, reporting on several cases touching on human rights abuses and the exploitation of vulnerable populations. After 10 years with NBC, she retired from journalism in 2024 to focus on personal projects.