It  happened on the Galgorm Road, near the junction with the Dan's Road, shortly before 21:00 BST on Friday.
The woman, whose name has not been released, had been walking a dog owned by one of her sons who is on holiday.
It is believed she walked out onto the road - possibly to cross it - when she was struck. The woman and the dog were both killed.
The main Galgorm Road was sealed off overnight whilst the police investigated the scene.
Police have appealed for witnesses.
A 70-year-old woman has died after she was hit by a car in Ballymena, County Antrim.