Family
- son Nick Simmons: Born 1989; mother is Shannon Tweed; appeared alongside his family on reality TV series, "Gene Simmons' Family Jewels"
- daughter Sophie Simmons: Born 1992; mother is Shannon Tweed; appeared alongside her family in reality TV series, "Gene Simmons' Family Jewels"
- father Feri Witz: abandoned family when Gene was young
- mother Flora Klein: a Jewish Hungarian immigrant; the only member of her family to survive the Holocaust; raise son alone after husband abandoned the family
Companions
- Companion Diana Ross: dated the singer/actress
- Companion Cher: Dated and lived with the singer/actress for several years in the late 1970s
- Companion Liv Ullmann: dated the Norwegian actress
- Companion Liza Minnelli: dated the singer/actress; managed her recording career
- Companion Shannon Tweed: Born c. 1957; together since 1984; lived with the model/actress since 1986 but never married; has two children with Simmons; appeared alongside her family in reality TV series, "Gene Simmons' Family Jewels"
- Companion Georgeann Walsh Ward: dated c. 1971-74
