Derek Thompson (born 4 April 1948) is a Northern Irish actor, most notable for playing Charlie Fairhead in the long-running BBC television medical drama series Casualty for 37 years, from its first episode in 1986 to his final episode in 2024. In 2017, it was revealed that this role has made Thompson the highest paid actor within the BBC with a salary of £350,000-£399,000 per annum. Following his exit from the show, Thompson joined the cast of hit Northern Irish police drama Blue Lights for its second season. Prior to the lead role in Casualty he starred in several films including The Long Good Friday, TV series such as Harry's Game and The Gentle Touch and several celebrated stints at The National Theatre. As a musician, he was also part of a folk duo with his twin sister Elaine in the 1960s. He married the actress Dee Sadler in 1989, having met her filming an episode of Casualty in 1987. Together they have one son, Charlie. He has another son from his previous marriage to his first wife Christine.