The historical connection between Iran and India and their relations which is based on good neighborliness and friendship is a long-standing connection that may date back to the second millennium BC, the era of Aryan migration.This long-standing bond was fueled and perpetuated by the advent of Islam and its spread through Muslim Arabs and Iranians and through the Persian language.Bilateral relations and the influence of Iranian-Islamic culture on Indians and the spread of Persian language in that land for almost a thousand years, especially as the language of Sharia and culture in social strata and inlaw courts and courts of justice and courts of India, added to the privilege of Iranian culture.Based on the importance of this notion, the present article tries to examine the reputation of Iranian culture and Persian language and literature in India in order to consider some unknown aspects of the spread of Persian languagein India not only among Muslims but also among non-Muslims.Furthermoreit revealsthe profound ties between Iranians and Indians. Then it can be concluded that this language has been a common literary and cultural source and also a factor of closeness and unity and a means of understanding and familiarity between the two nations of Iran and India for a long time.The research results show that from the earliest times, perhaps, the era of Aryan migration, the Indian subcontinent has always been the second home for the Iranians.The influence and spread of Persian language in India is not limited tosome simple prose, on the contrary complicated forms of Persian poemscan also be found all over this land.This language has been the official language of the government and court of this land for more than eight hundred years.This language has had the power and ability to transform the dualistic thinking of Hindu scholars into monotheism and poets from the Brahman classcould compose Persian poetry.Through the influence of this dominant language, Dehlavi, the great poet of Indian style in India, became known as Hafiz of India.Although Amir Khosrow is known as the parrot of India, takes also the title of Saadi of India and Saadi's Islamic and Iranian philosophy and advice can be found in his poems.SaibTabrizipredisposes one of the Indo-Aryan languages, i.e.Urdu with allegory. He has also a huge amount of influence over thethinking, movement, and revolutionary movement and its dynamism in Iqbal's thinking.Any way Indian scholars believe thatthe Indian subcontinent is proud of the influence of Persian language in India, because it shows that the Indian subcontinent have nurtured the Persian language, Persian literature and Iranian culture in many aspects such as architecture, painting, calligraphy, etc., as a kind midwife in its loving arms for many years.Therefore, considering theinfluence of Persian language and literaturein India for a thousand years, these kinds of research is in fact rediscovering the glory of Iran and Iranians.