There is provided an ice maker and a water purifier having the same capable of effectively making ice using two water trays. The water purifier having an ice maker includes a water tray member comprising an ice-making water tray holding ice-making raw water to make ice using an ice-making unit, and an auxiliary water tray holding ice-making raw water remaining in the ice-making water tray in the course of cooling the ice-making raw water by means of the ice-making unit and removing the ice-making raw water from the ice-making water tray; an ice reservoir storing ice made in the ice-making unit; a cold water storage tank cooling water held therein using the ice made in the ice-making unit; and a guide member guiding the ice made in the ice-making unit so that the ice is selectively fed to either the ice reservoir or the cold water storage tank. The ice maker and the water purifier having the came may be useful to improve the ice-making efficiency since residual cooling water cooled in the ice-making water tray is collected in the auxiliary water tray, and re-used to make ice.