The "Companions of the Doctor" refers to the characters who travel with the Doctor in the long-running British television series, Doctor Who. These companions often serve as the audience's perspective, experiencing the adventures and challenges alongside the Doctor. They come from various backgrounds and time periods, adding depth to the show's narrative. Companions play a crucial role in the series, providing emotional support and helping the Doctor confront various foes. Notable companions include Sarah Jane Smith, Rose Tyler, and Clara Oswald, each bringing unique qualities and stories that enrich the Doctor's journey through time and space.