Tyrtaeus was a Greek elegiac poet from Sparta who composed verse during the mid-to-late 7th century BCE, specifically the period of the Second Messenian War. While ancient sources conflict on his origins, the dominant tradition identifies him as a Spartan. His poetry served a direct civic and military purpose, exhorting Spartan citizen-soldiers during a time of crisis and reinforcing the martial values of the developing Spartan state.

His surviving work consists of fragments preserved by later authors. Two major works are identified: the political elegy Eunomia, which addressed civic harmony and the Spartan constitution, and a body of exhortatory elegies urging bravery, discipline, and self-sacrifice in battle.

Tyrtaeus is a foundational figure for both Greek elegiac poetry and Spartan ideology. His state-commissioned verse provided a powerful framework for the Spartan way of life, equating excellence with courage in the hoplite phalanx. His poems were used to inspire troops and educate Spartan youth, offering crucial evidence for the values of early Sparta during its rise to dominance.