An LED driver and a display device using the same are disclosed. The LED driver is adapted for driving a first set of LEDs and a second set of LEDs. The LED driver includes an inductor, a main switch, a first switch, a second switch, and a controller. The inductor has a first terminal receiving an input voltage. The main switch is coupled between a second terminal of the inductor and a common level for adjusting a current flowing therethrough. The first switch is coupled between the first set of LEDs and the second terminal of the inductor. The second switch is coupled between the second LEDs and the second terminal of the inductor. The controller is coupled to controlling terminals of the main switch, the first switch, and the second switch respectively for controlling conducting statuses of the main switch, the first switch, and the second switch respectively.