Khorasan (or Khorassan) (خراسان in Persian) is one of the provinces of Iran, located in the northeastern part of Iran. Its name means "where the sun comes from (arrives from)". Mashhad is the capital. Another city is Nishapur.

The ancient Persian province Khorasan included parts which are today in Iran, Afghanistan, Turkmenistan and Uzbekistan. Four of the main historical cities of Persia are located in Khorasan: Nishapur, Merv (in today's Turkmenistan), and Herat and Balkh (both in today's Afghanistan). In its long history, Khorasan knew many conquerors and empires: Persians, Greeks, Arabs, Seldjuk Turks, Safavid Turks, etc.