The Etrian Odyssey series has had a number of cameos within its history. They concern characters from Atlus's other franchises such as the Trauma Center Series and Princess Crown . Listed below are the characters that have cameoed.
- Robert Hoffman - referred to as Dr.Hoffman in game. He works in the Apothecary in Etrian Odyssey. Also, in the Midgard Library, there is a professor that looks like him. This is not a confirmed cameo.
- Derek Stiles - referred to as Dr. Stiles in game. He works as the head doctor in Lagaard Hospital in Etrian Odyssey 2. He distributes medicines and heals explorers from petrification and death.
- Angie Thompson - referred to as the Assistant Nurse in game. She works as Dr. Stiles's assistant in Lagaard Hospital in Etrian Odyssey 2 just as she does in Caduceus.Here, she is dressed in a traditional medic outfit inspired by her attire from the original Trauma Center: Under the Knife . She also works as the innkeeper in Etrian Odyssey 3 in the Deep City. Here, she is dressed moreso like she is in Trauma Center: Under the Knife 2 .
- Princess Gradriel De Valdendia- referred to as Lady Gradriel, the daughter of the Duke of Lagaard, in Etrian Odyssey 2. Also known as "High Lagaard's Sun".