Chris Kyle was a Navy SEAL and sniper who served four tours in Iraq, where he became the most prolific sniper in U.S. military history. After the war, he opened a sniper school and founded a charity to support veterans facing the challenge of readapting to civilian life. Kyle was eventually killed by a veteran he was trying to help.
Taya Kyle, Chris Kyle's wife, serves as a guest narrator of many passages in the book. As such, she offers a civilian perspective of military life and the war.
Ryan Job, a SEAL serving on SEAL Team 3, was injured and blinded in Iraq. He died in surgery addressing his war injuries years later.
Marc Lee, a new member of SEAL Team 3, became a close friend of Kyle's. Lee was the first SEAL killed in combat in the Iraq war.