Irina Derevko is a fictional character from the television series Alias, created by J.J. Abrams. She is portrayed by actress Lena Olin and is introduced as the mother of the main character, Sydney Bristow. Irina is a complex figure, often shifting between ally and adversary throughout the series. As a former KGB agent, Irina has a mysterious and dangerous background. Her character is known for her intelligence, resourcefulness, and ability to manipulate situations to her advantage. The relationship between Irina and Sydney is central to the show's narrative, exploring themes of trust, betrayal, and family dynamics.