His older nephew, Leonard, recalled that Floyd was the only person who had been affectionate to him growing up, and he was upset to learn from his mother Beverly that his uncle had died from what appeared to have been a heart attack as mentioned in "The Maternal Capacitance".
- Brother or ex-brother-in-law: Alfred Hofstadter
- Sister or ex-sister-in-law: Beverly Hofstadter
- Nephews: Leonard Hofstadter, Michael Hofstadter
- Niece: Unnamed
- Niece-in-Law: Penny Hofstadter née ?
- Possible Niece-in-Law: Unnamed
- Nephew-in-Law: Unnamed
- Possible Father: Unnamed
- Possible Mother: Unnamed
- Possible Sisters: Edna, Nancy, Unnamed
- Possible Wife: Edna
- Possible Wife: Nancy
- Possible Children: Unnamed