Quinnsworth was a supermarket chain that operated in Ireland from 1966 to 2001. During its time in operation, it grew to be one of Ireland's leading retailers, with approximately one quarter of the grocery market in the Republic of Ireland, and some 88 supermarkets across the island of Ireland, including its Crazy Prices brand operated at some of its larger outlets. It was acquired by UK chain Tesco in 1997, with its supermarkets being gradually rebranded as Tesco Ireland over the following four years.