As much as known to Felonius Gru, the Gru family consists of more than twenty-five members, starting from Charlotte and Léopold Gru.
- Little Pony
- ? (unknown relative)
- Henry Gru
- John Gru
- Jeffrey Gru
- Marlena Gru, Gru and Dru's mother; Robert's wife.
- Robert Gru, Gru and Dru's father; Marlena's (late or ex) husband.
- Lucy Wilde, Gru's wife; Margo, Edith and Agnes' adoptive mother.
- Felonius Gru
- Dru Gru, Gru's twin brother and Margo, Edith and Agnes' adoptive uncle.
- Margo Gru, Gru and Lucy's oldest adoptive daughter; Edith and Agnes' sister.
- Edith Gru, Gru and Lucy's middle adoptive daughter; Margo and Agnes' sister.
- Agnes Gru, Gru and Lucy's youngest adoptive daughter; Margo and Edith's sister.
Although very little is known about any members of the family, it is known that Marcel Gru was a werewolf, as shown in Gru Family Tree in Gru's House, and Ronald Gru was a pirate. It is also known that Felonius Gru is one of the direct descendants of Charlotte and Léopold Gru, and he is in the 6th generation.
- The Gru Family Tree in Gru's house was not updated with the existence of Margo, Edith and Agnes, though later, they did it themselves and also drew a heart around Gru's face, indicating their love towards Gru.
- Judging from the given names of the early ancestors in the family tree, Gru family is probably originated from French-speaking regions.