Metrodorus of Lampsacus the Elder was a philosopher from the 5th century BCE, during the Classical period of ancient Greece. He was a native of the city of Lampsacus in Asia Minor and a student of the pre-Socratic thinker Anaxagoras. He is called "the Elder" to distinguish him from a later philosopher from the same city who followed Epicurus.

He is historically important for being the first known author to write a detailed physical, or natural philosophical, interpretation of Homer's poetry. His work, titled On Homer, does not survive intact and is known only through fragments and references in later ancient writers. In it, he systematically interpreted the gods, heroes, and events of Homer's epics as allegories for natural elements and principles. For example, some scholars report that he interpreted Achilles as representing the sun and the Trojan War as a conflict between elemental opposites. This approach was an early attempt to reconcile traditional mythology with the new scientific theories of his time.

According to modern scholars, his allegorical method represents a significant bridge between pre-Socratic physical speculation and literary criticism, influencing later thinkers who sought deeper meanings in poetic texts.