Deianeira is the devoted wife of Heracles, currently living in Trachis as a guest. She spends much of her marriage waiting patiently through her husband's frequent departures and returns. Burdened by anxiety over a vague prophecy, she deeply loves Heracles but struggles with the emotional toll of his dangerous lifestyle.

Heracles is a famous Greek hero renowned for his superhuman strength and his completion of numerous labors. He frequently travels across Greece, undertaking dangerous tasks and leaving his family behind for extended periods. His immense power and intense desires often put him at the center of violent conflicts, shaping the lives of those waiting for him at home.

Hyllus is the son of Deianeira and Heracles. He serves as an active agent for his mother, taking on the responsibility of tracking down his father and delivering news. He acts as a bridge between the domestic sphere of Trachis and the external world of heroic conflicts.

The Chorus consists of young women from Trachis who serve as companions and confidants to Deianeira. They offer emotional support and philosophical perspective, often reminding Deianeira that Zeus dispenses both joy and sorrow. They function as the voice of the community, interpreting events through the lens of divine will.

The Nurse is a trusted household servant who attends to Deianeira. Practical and observant, she provides grounded advice to her distressed mistress, such as suggesting the proactive step of sending Hyllus to search for his father.

Lichias is a herald serving Heracles. He is tasked with transporting prisoners of war back to Deianeira while his master completes sacrifices to Zeus. He attempts to manage the flow of information regarding Heracles' military motivations to protect Deianeira's feelings.

Iole is a young captive woman from Euboea, the daughter of King Eurytus. Brought to Trachis as a prisoner of war, her evident high rank and deep sorrow immediately draw Deianeira's pity. She represents the devastating human cost of military campaigns.

The Messenger is a local man who gathers and relays news to the household. Eager to deliver good tidings, he provides Deianeira with the initial joyous report of her husband's safety before revealing more complicated truths he overheard in the marketplace.

Nessus is a centaur from Deianeira's past. Years prior, he ferried travelers across a river and attempted to sexually assault Deianeira, resulting in Heracles shooting him. He remains a lingering presence in Deianeira's life through a parting gift he left her.

Achelous is a powerful river god who originally sought Deianeira's hand in marriage. His terrifying monstrous forms frightened Deianeira until Heracles arrived to challenge him in violent combat.

Eurytus is the King of Euboea and the father of Iole. He angers Heracles by expelling him from a banquet, an insult that ultimately results in the destruction of his city and the capture of his daughter.