Born on September 11, 2006 Renesmee (pronounced Ruh-nez-may) Carlie Cullen, nicknamed "Nessie", is the resident vampire/human hybrid of the Olympic coven. She is the daughter of Edward Cullen and Bella Swan and the imprintee of Jacob Black. Renesmee's biological paternal grandparents are Edward Sr. and Elizabeth Masen, while on the maternal side, they are Charlie Swan and Renée Dwyer. She is also the adoptive granddaughter of Carlisle and Esme Cullen and the adoptive niece of Jasper and Rosalie Hale, and Alice and Emmett Cullen.

Renesmee is considered to be Edward and Bella's "miracle", because of what it took to keep her and her mother alive through the pregnancy. She has the abilities to show people her thoughts by touching them and presumably break through their mental defenses. Bella initially gets angry and attacks Jacob for giving her daughter the nickname "Nessie" as well as imprinting on her. Irina of the Denali Coven sees Renesmee and believes she is an immortal child, a human child who had been turned by a vampire. She informs the Volturi, as immortal children are not permitted to live. The Volturi reach Forks intent on killing Renesmee and the Cullens. However, the Cullen family members gather witnesses from around the world to prove that Renesmee is not an immortal child. Alice brings another vampire-human hybrid, Nahuel, who explains that they pose no danger to the vampires. Convinced that Renesmee is not a threat, the Volturi leave, and Renesmee and her family are left in peace. She is the only hybrid currently known to have supernatural gifts.