Peter Phelps has appeared as three different characters over the course of the series:
- episode 13.68 Carpe Diem: Part 2 (1993) - Christopher Elliott
- episode 13.67 Carpe Diem: Part 1 (1993) - Christopher Elliott
- episode 13.66 Thursday's Child (II): Part 2 (1993) - Christopher Elliott
- episode 13.65 Thursday's Child (II): Part 1 (1993) - Christopher Elliott
- episode 13.64 Thursday's Child: Part 2 (1993) - Christopher Elliott
- episode 13.63 Thursday's Child: Part 1 (1993) - Christopher Elliott
- episode 6.72 It Isn't Catching, Is It?: Part 2 (1986) - Christopher Elliott
- episode 6.71 It Isn't Catching, Is It?: Part 1 (1986) - Hector Guinness
- episode 1.12 Secrets: Part 2 (1981) - Jeff Wilson
- episode 1.11 Secrets: Part 1 (1981) - Jeff Wilson