This research paper explores the significant contributions of Geoffrey Chaucer to the development of the English language and literature. It examines Chaucer's pivotal role in establishing English as a literary language, moving away from Latin and French dominance. The study delves into Chaucer's major works, such as "The Canterbury Tales," analyzing their linguistic innovations, including vocabulary, grammar, and poetic forms. Furthermore, the paper investigates Chaucer's impact on subsequent generations of English writers, solidifying his legacy as the 'Father of English Literature'. This analysis aims to illuminate Chaucer's lasting influence on the English literary landscape.