Ellie Williams is the central character of The Last of Us series.
She serves as the protagonist of The Last of Us: American Dreams,
the playable deuteragonist of The Last of Us, and the playable protagonist of both The Last of Us:
Left Behind and The Last of Us Part II.

Joel is a survivor of the cordyceps brain infection, which has wiped out 60% of mankind globally.
After losing his daughter Sarah in the outbreak,
Joel becomes a ruthless and cynical smuggler eventually tasked with smuggling and protecting Ellie, a young girl
who is the key to mankind's survival.

Tommy Miller is a supporting character in The Last of Us and The Last of Us Part II.
He is Joel's younger brother, and Sarah's paternal uncle.
A caring and compassionate man, Tommy survived the early years of the outbreak with Joel.

Marlene was the leader of the Fireflies, a group who fought against the Military
totalitarian rule during the apocalypse.
Marlene met and befriended a woman named Anna, who asked the former to protect her daughter, Ellie as her dying wish.

Theresa "Tess" Servopoulos is a supporting character in The Last of Us.
A hardened survivor, she was the long-term smuggling partner of Joel Miller.
The pair made their living as smugglers in Boston, where they traded with survivors outside of the city.