Genevieve Knight "G" Hannelius (born December 22, 1998) is an American actress and singer. She starred as Avery Jennings in the Disney Channel sitcom Dog with a Blog. Prior to this, she had recurring roles in the Disney Channel series Sonny with a Chance and Good Luck Charlie. She has also starred in Leo Little's Big Show and has done voice work as Rosebud in the Air Buddies films. She also guest starred in Disney Channel's series Jessie.
Hannelius was born in Boston, Massachusetts. Her father is Swedish. She moved to Falmouth, Maine at age three.
Hannelius' theater roles include playing Madeline in the Children's Theater of Maine's production of Madeline's Rescue in summer 2002. and Jenny in Tales of a Fourth Grade Nothing with Children's Theatre of Maine and Maine State Music Theater. She moved to California for three months to try out for auditions, and was so successful that her family relocated permanently to Los Angeles in 2008. Hannelius is an alumna of the Los Angeles-based Young Actor's Studio.