Simon Seville is a fictional character from the animated television series Alvin and the Chipmunks. He is one of the three chipmunk brothers, known for his intelligence and responsible nature. Simon often takes on the role of the voice of reason among his siblings, Alvin and Theodore. In the series, Simon is characterized by his glasses and blue sweater. He is a skilled inventor and often helps the group solve problems. His personality contrasts with Alvin's mischievousness and Theodore's sweetness, making him a crucial part of the trio's dynamic.