Journalist Robert Leckie enlists in the Marine Corps following the attack on Pearl Harbour; Sgt John Basilone prepares to leave for the war; the Marines invade the island of Guadalcanal.
Basilone arrives with the 7th Marines to reinforce the men defending the airstrip on Guadalcanal; the Japanese bombard their position and Basilone suffers a loss; Sledge secures permission to enlist.
Exhausted from their months on Guadalcanal, thousands of soldiers land in Melbourne; Leckie gets close to an Australian woman and her family; Basilone is told to return home to sell war bonds.
Sledge undergoes combat training; Leckie and his group's arrival on Cape Gloucester, New Britain, sees their physical and mental health deteriorate; Leckie is placed in a psychiatric ward.
Basilone's fame grows on his war bond tour with starlet Virginia Grey; veteran soldiers warn Sledge that war isn't glamorous and he soon sees his first fighting, as the Japanese inflict heavy casualties.
As the Marines prepare to attack the airfield they grow dehydrated and suffer severe casualties while crossing the airfield; Leckie is evacuated; Sledge confesses his fear and begins writing about his experience.
James Badge Dale
Robert Leckie
Joseph Mazzello
PFC Eugene Sledge
Jon Seda
John Basilone
Rami Malek
PFC Merriell 'Snafu' Shelton
Sebastian Bertoli
Marine