Loung was the protagonist in First They Killed My Father and narrates the story. She is a "round" character, well developed and with human emotions. She gets sad and anxious as one would in her situation, but she also gets angry. The way that she talks about her rage toward the Khmer Rouge makes her sound like a real person. And she's not black and white; she's not just a hero. At one point in the story Loung stole her baby sister's food. Afterwards, Loung was torn up with guilt.

The way that Loung changes so much in the story also makes a dynamic character. She starts off as just a regular girl in a middle class family, but has to learn to be brave in difficult circumstances. Before, Loung was bratty and selfish. But later on, she ate things that she thought she never would to stay alive, worked strenuously, and coped with people dying all around her. But even more than that, she turned into a cold, bitter person. Throughout most of the story, Loung resented the Khmer Rouge so must that it consumed her. Her struggles warped her into a different person.

Pa was the leader of the family. He tried to keep the family together and did the best he could to help. Loung and Pa's relationship was the most important and special of anyone else's in the book. He seemed to favor her, and always stuck up for her when her ma would pick on her. When Pa died, it changed a lot in the book. What was left of the family had to split up in order to keep everyone safe.

Chou is Loung's older sister. She doesn't have much to say about things, and she is very obedient. While her gentle nature was praised in Phnom Penh, it wasn't a helpful survival skill. Even though Chou is quiet and reserved, she is a round character because of her human feelings. She is Loung's best friend, so she tells Loung about her feelings. While Chou and Loung are together at the work camp, Loung acts like she is Chou's older sister by protecting her and giving her advice. Chou's survival depended on others looking after her.

Ma didn't have the easiest relationship with Loung. Loung was always too much of a tomboy for Ma. She was dependant on Pa. When he was taken, she fell apart.

Meng is Loung's older brother. He is eighteen, so he is the oldest brother. He is also a round character. While not much is told about him during the middle of the book, he is prominent at the end when he takes Loung to America. Since he changes from a carefree son to being the head of the family, he is considered a dynamic character as well.  He loves his younger siblings, and they look up to him. In addition, he is responsible and reliable. These characteristics helped him survive, and protect his siblings after Pa dies.

Keav is the oldest sister in the family. She is very pretty, but she tends to gossip and argue more than she should. Since Pa works for the government, he is worried about people hurting her as revenge on him. She is a flat character. Her emotions aren't well developed, and we aren't told much about her personality. Besides physical appearance, she stays the same, so she is a static character. She doesn't have what it takes to survive in difficult situations, and she isn't given the help that Chou had. Shortly after she is separated from her family, she dies.

Khouy was a very dynamic character. He begins the story as a threatening figure to Loung because he was always the one to hand out punishments. As the story progressed, he became less threatening and in the end, they had to band together as a family to survive.

Kim was the one who had to take the Pa's place when he died because he was the oldest and the only boy around. When he was only eight year old, he had to withstand cruel beatings so that his family could have enough food to survive.

Geak was just a baby when this story took place. She is what is called a "static" character because she stayed the same throughout the entire story. She is also a "flat" character, as she is not very well developed as a character.