Maddy was a female Human Starfleet crewperson in the 23rd century.

In 2286, Maddy was assigned to assist Mr. Paul during the clean-up operations after the destruction of the Omicron Ceti IV colony. Maddy noted that a deceased Ensign Bloemker, from USS Enterprise-A, was being placed in their makeshift morgue even though her ship had not filed paperwork regarding her death. Mr. Paul noted that James T. Kirk's ship was notoriously slow to file paperwork on their missing and killed crewmembers. (TOS comic: "Old Loyalties")

Maddy was only identified by her first name, her surname is unknown. Maddy's uniform showed no visible rank or assignment patch insignia, but had a grey collar indicating she was in the operations division, a tactical officer, a science officer or a navigator, with all likelihood falling on the most former of these possibilities.