Language is an ever-changing phenomenon. It is constantly evolving. In the evolutionary process, one language enters into another language and adds some new dimension to it. Latin, one of the oldest languages in human history, made a great impact in old English adding a new dimension and contributing to the bulk of it. Most of the Indo-European languages come from eleven principal groups: Indian, Iranian, Armenian, Hellenic, Albanian, Italic, Balto-Slavic, Germanic, Celtic, Hittite and Tocharian. These are the branches of the Indo-European family tree (Bough & Cable 1951). Old English, however, is originated mainly from three languages- Celtic language, Latin language, Germanic language. The influence of Latin in old English is significantly vital. A language can travel from one place to another place mainly through trade and commerce, political and military influence and culture and religion. As a matter of fact, Latin language entered England through all of them. It particularly influenced vocabulary, grammar and literature of old English and in the process brought about a great change in the way of the people of old English period. The article attempts to examine the influence of Latin at different stages in the development of old English language. Keywords: Indo- European Language, Latin Language, Celtic Language, Germanic Language, Old English Period, Anglo Saxon Period