Here's why:
* Time Travel: The central premise of the show revolves around a time-traveling alien, the Doctor, who explores the universe and encounters different civilizations and historical periods.
* Futuristic Technology: The show features advanced technology like the TARDIS, sonic screwdrivers, and various alien gadgets, pushing the boundaries of scientific possibilities.
* Extraterrestrial Life: Doctor Who is filled with a plethora of alien species, each with unique characteristics and abilities.
* Exploration of the Unknown: The show explores themes of space exploration, the unknown, and the potential dangers and wonders of the universe.
While Doctor Who often blends sci-fi elements with fantasy and other genres, its core foundation firmly places it within the realm of science fiction.