William Morgan Sheppard is a British film, television and voice actor. He played the older version of Canton Everett Delaware III in the Doctor Who story The Impossible Astronaut. His son, Mark Sheppard, played the younger version of Canton Delaware.
Outside Doctor Who, he's best known for his numerous appearances in other science-fiction series, including Star Trek. In 2000, he provided voices for the video game Star Wars: Force Commander and also played the role of Ignatius Cheese in the video game Escape from Monkey Island. In the mid-1980s, Sheppard played Blank Reg in both the original UK production of Max Headroom and its later American remake.