First mentioned in "The Maternal Congruence" where Sheldon says that Leonard's family have chosen high-achieving partners and that Leonard was worried that his mother wouldn't approve of Leonard dating Penny due to her educational status and that her biggest achievement being memorising the Cheesecake Factory menu.
He is indirectly mentioned again in "The Cohabitation Formulation" when Leonard tells Raj that his sister is 38 and married when Raj said he would have his way with Leonard's sister because he wanted to get back at Leonard for going out with his sister Priya.
- Wife: Unnamed
- Father-in-law: Alfred Hofstadter
- Mother-in-law: Beverly Hofstadter
- Brother-in-laws: Leonard Hofstadter, Michael Hofstadter
- Sister-in-laws: Penny, Unnamed (via Michael)
- Unnamed nephews/nieces
- Uncle-in-law: Floyd
- Aunt-in-laws: Edna, Nancy, Unnamed
- Cousin-in-laws: Unnamed
- Grandfather-in-law: Unnamed
- Grandmother-in-law: Unnamed
- This individual also has an unknown high-achieving job since Sheldon stated in "The Maternal Congruence" that Leonard's family have all chosen high-achieving partners.