波斯语(Persian language)，亦称法尔斯语（Farsi language）。
一种伊朗语，在伊朗约有2,500多万人把它当作母语，并有数百万人把波斯语当作第二语言。现代波斯语是由7～9世纪伊朗西南部的方言发展而来的共同语（koine），在引进伊斯兰教後从阿拉伯语吸入不少外来词。11～12世纪波斯语在东北部波斯和亚洲中部得以标准化和文学化。波斯以外的国家（如蒙兀儿王朝的印度和鄂图曼土耳其）都曾在一定历史时期扮演文化中心的角色。波斯语在这些国家的地位对乌尔都语和鄂图曼土耳其语都产生了较大影响。突厥诸语言和印度-雅利安诸语言、高加索诸语言以及伊朗诸语言都曾大量借用波斯语。如其他现代伊朗语一样，波斯语在声音结构上也与古伊朗语有显着不同，动词形式大量减少，名词和形容词已不再有格的变化。书写形式与阿拉伯字母系统稍有不同。
English version：
Persian language
Iranian language spoken by more than 25 million people in Iran as a first language, and by millions more as a second. Modern Persian is a koine developed from southwestern dialects in the 7th-9th century, after the introduction of Islam brought a massive infusion of loanwords from Arabic. Its standardization and literary cultivation took place in northeastern Persia and Central Asia in the 11th-12th century. Polities outside Persia itself (e.g., Mughal India, Ottoman Turkey) have at times been major literary centers. Its status in those countries led to a very strong Persian influence on Urdu and Ottoman Turkish. Other Turkic and Indo-Aryan languages, Caucasian languages, and Iranian languages have also borrowed heavily from Persian. Like other Modern Iranian languages, Persian shows marked changes in sound structure from Old Iranian, as well as a drastic reduction in the repertoire of verbal forms and complete loss of case inflections for nouns and adjectives. It is written in a slightly modified form of the Arabic alphabet.