Aida, an Ethiopian princess (soprano), The King of Egypt (bass), Amneris, daughter of the King (mezzo-soprano), Radamès, Captain of the Guard (tenor), Amonasro, King of Ethiopia (baritone), Ramfis, High Priest (bass), a messenger (tenor), Voice of the High Priestess (soprano) Priests, priestesses, ministers, captains, soldiers, officials, Ethiopians, slaves and prisoners, Egyptians, animals and chorus
Egypt, during the reign of the pharaohs. At the royal palace in Memphis, Radamès hears from the high priest Ramfis that Ethiopia will attack Egypt soon. He hopes to command the Egyptian army, believing that his victory could help free the Ethiopian king’s daughter and Ethiopian slave, Princess Aida, whom he is secretly in love with, and gets her hand in marriage.
A messenger brings news about the advancing Ethiopians troops. The king calls for a war preparation and appoints Radamès as its commander.
Aida is torn between her love for Radamès and her loyalty to her country and king father, Amonasro. On the other hand, Radamès’ love for her has invited jealousy from Amneris, the daughter of the Egyptian king who is in love with him.
In the temple of Vulcan, the priests consecrate Radamès to the service of the god Ptah. Ramfis orders Radamès to protect their homeland.
Ethiopia is defeated. Amneris awaits Radamès’ triumphant return. Amneris is alone with Aida. She tells Aida that Radamès has fallen, and then that Radamès is actually still alive. Seeing Aida’s reactions, Amneris notices Aida’s love for Radamès. She is confident that she will be able to defeat her love rival.
The king and Amneris observe the celebration at the city gate and praise Radamès for the victory. The captured Ethiopians, including the king Amonasro, are brought in. As the king Amonasro’s identity has not been made known, he signals to his daughter, Aida, to keep mum.
Amonasro eloquently pleads for mercy. Impressed by his pleas, Radamès asks for the release of the prisoners, to overrule the execution of the prisoners. The king grants his request but keeps Amonasro in custody.
As a reward for his victory, Radamès will have Amneris’ hand in marriage.
A day before the wedding, Amneris and Ramfis pray in a temple on the banks of the Nile.
Aida is nearby waiting for Radamès. She is lost in her thoughts of her homeland when Amonasro suddenly appears. Playing on her sense of duty, he makes her promise to discover the route of Egyptian army invasion on Ethiopia. Amonasro hides as Radamès arrives. Aida convinces Radamès to run away with her so they could spend their future life together. When she manages to get the information from Radamès, Amonasro reveals himself from his hiding place.
Radamès is horrified by what he has done. Both Aida and Amonasro try to calm him down as Ramfis and Amneris emerge from the temple. Aida and Amonasro manage to escape. Radamès surrenders himself to the high priest’s guards.
Radamès awaits his trial and believes that Aida is dead. Amneris offers to save him, but he has to give up on Aida, who is still alive. Radamès rejects Amneris’ offer.
In the trial, Radamès refuses to answer the priests’ accusations. He pleads for his life, but the priests insist on condemning him to be buried alive. Hoping to die with Radamès’, Aida hides in the vault. They express their love for the last time while Amneris, in the temple above, prays for peace.