Jagger's 21-year-old granddaughter Assisi Jagger welcomed the little bundle of joy, whose name has not been announced, over the weekend, according to England's Hello!. It's the first child for Assisi and her chef boyfriend Alex Key.
Assisi's mother Jade is expecting her third child next month at the ripe old age of 42. Jade was only 20 when she had Assisi.
"The women in our family just tend to have children young. It runs in the genes," Assisi said. "I imagine it's nice to be a great-granddad, although I'm not sure he likes the idea of getting old, or being called one," she said of her rock star grandfather.
Jagger has seven children with four women and four grandchildren. The new addition to the family is welcome news after Jagger's partner L'Wren Scott committed suicide in March. The Rolling Stones are set to restart their latest tour on May 26 in Oslo.