The person known as the "father of geometry" is Euclid, a Greek mathematician who lived around 300 BC. Euclid is famous for his work "Elements," a comprehensive compilation and systematization of the knowledge of geometry of his time. This work introduced fundamental principles, axioms, and theorems of geometry, using a deductive approach that laid the foundation for modern geometry and mathematical logic. Euclid's contribution was so significant that the standard geometry we learn today is often called Euclidean geometry, and his legacy continues to influence mathematics to this day.