The ancient Greek philosopher sentenced to death for corrupting the youth of Athens was Socrates. In 399 BCE, he was charged with impiety and corrupting the young citizens of Athens through his teachings and dialectical methods. His approach encouraged critical thinking and questioning of traditional beliefs, which alarmed many Athenian leaders. Socrates chose to defend his ideas rather than flee to avoid punishment. Ultimately, he was found guilty and sentenced to death, drinking a poisonous concoction of hemlock. His legacy continues to influence philosophy and ethical thought today.