* Sean Penn as Lieutenant Colonel Hal Moore
* Robin Wright as Julia Moore
* Michael Murphy as General Westmoreland
* Don Cheadle as Lieutenant Colonel John "Jack" Galvin
* Sam Robards as Lieutenant Colonel Thomas "Tom" Brown
* Brian Cox as General William Westmoreland
* John Heard as Colonel Robert "Bob" Mac
* Lee Tergesen as Lieutenant Henry Herrick
* Bill Smitrovich as Sergeant Major Plummer
* Tim Blake Nelson as Specialist Four Glenn (PFC)
* John Slattery as Sergeant O'Neill
* Ron Livingston as Lieutenant (LT) David "Dave" Cole
It's important to note that "A Bright Shining Lie" is a dramatization of the book of the same name by H.R. McMaster, which explores the career of Lieutenant Colonel Hal Moore, a decorated Army officer during the Vietnam War.