Alfred Hofstadter

Dr. Hofstadter is the ex-husband of Beverly Hofstadter and the father of Leonard and Michael Hofstadter, as well as their unnamed sister. He is an anthropologist who once worked with.

Like the majority of the male protagonists' fathers, he has never been seen, but is mentioned several times.

With Beverly Hofstadter
Not much is known about their relationship, but Beverly does mention that they got divorce in "The Maternal Congruence"

With Leonard Hofstadter
Not much is known about their relationship, although it is likely that Leonard likes his father more than his mother. Leonard refers to him as "father" instead of "dad". Nothing is currently known about Dr. Hofstadter's relationship with his other two children. In "The Fish Guts Displacement", Leonard said that the only father-son time he spent doing was with a Etruscan boy (who Leonard hated). He also borrowed Leonard's hugging machine to compensate for the lack of intimacy in his marriage with Beverly.