* Annemarie Johansen: The protagonist of the story, she is a brave and resourceful young girl who risks her life to help her best friend, Ellen Rosen, escape from Nazi-occupied Denmark. She is a key figure in the resistance, even if she's not an official member.
* Kirstin Johansen: Annemarie's older sister, she is a member of the Danish resistance movement and helps to organize the escape of Jewish refugees.
* The Danish Resistance: While not individually named, the Danish resistance plays a crucial role in the story. They are the network of people who provide shelter, transportation, and crucial information to those fleeing the Nazi regime.
It's important to remember that the resistance in "Number the Stars" is not a centralized group, but rather a collection of individuals working together for a common goal. While Kirstin is explicitly a member, many others, like Annemarie and her family, contribute in ways large and small, risking their own safety to help others.