Aldebaran (α Tau, α Tauri, Alpha Tauri) is a red giant star. It is about 65 light years away in the zodiac constellation of Taurus. With an average apparent magnitude of 0.87 it is the brightest star in the constellation and is one of the brightest stars in the nighttime sky. The name Aldebaran is Arabic (الدبران al-dabarān) and means "the Follower", presumably because it rises near and soon after the Pleiades. It has a diameter around 44 times that of the Sun's.

Aldebaran was found to have a planet or possibly a brown dwarf orbiting it, which they named Alpha Tauri B. The space probe Pioneer 10 is heading to the direction of this star and will pass by it in 10 million years from now.