A character walks into a room. Before they speak, their costume has told you who they are. Costume design is the creation and selection of clothing worn by characters. It is not just fashion. It is storytelling. The costume reveals the character's class, occupation, personality, and state of mind. It places them in a time and place. It supports the mood and theme of the film. A great costume is inseparable from the character.

The costume designer works with the director to define the look. They research the period, the setting, and the social context. They sketch designs, select fabrics, and build or source garments. They work with the actors, the cinematographer, and the production designer. They consider color, texture, silhouette, and how the costume will look on camera. They may create multiple versions of the same costume for different stages of the story.

Costume design can be subtle or extravagant. In a contemporary drama, the costumes may look like ordinary clothes. In a period epic, they may be elaborate and historically detailed. In a fantasy, they may be invented from scratch. The best costume design serves the story. It makes the character feel real. It makes the world feel inhabited. It is one of the most collaborative and least recognized crafts in filmmaking.