Catherine Willows is a fictional character from the television series CSI: Crime Scene Investigation. She serves as a forensic scientist and later becomes a supervisor in the Las Vegas crime lab. Known for her expertise in forensic analysis, Catherine plays a crucial role in solving various criminal cases throughout the series. Catherine is portrayed by actress Marg Helgenberger and is recognized for her strong personality and dedication to her work. Her character often balances professional responsibilities with personal challenges, making her a relatable figure in the series. Catherine's contributions to the team highlight the importance of forensic science in criminal investigations.