Desmond Ronan is a character from the light novel series A Tale of the Secret Saint, which was announced for an anime adaptation scheduled to premiere in 2026. In the story, he holds the position of the Second Knight Commander and also serves as the Military Police Commander. He is the head of a noble family that holds the title of earl. One of his primary duties is to clean up and resolve various incidents caused by a threat known as Fear.

Desmond is characterized by his exceptional investigative abilities. He possesses the most extensive information network among all the knights, which aids him greatly in his role as the commander of the military police. His personality has been shaped by a significant personal betrayal: his fiancée was taken from him by his own younger brother. This event caused him to become deeply suspicious and made it very difficult for him to trust women. This backstory is a key element of his character, influencing his worldview and interactions with others, particularly female characters. His skills and rank position him as an important figure within the knight order, and his personal history with his brother likely serves as a source of internal conflict that affects his motivations and actions throughout the narrative.