A display apparatus includes a display panel and a power supply. The display panel displays an image at a first driving frequency in a normal mode and displays an image at a second driving frequency in a low power mode. The second driving frequency is lower than the first driving frequency. The power supply outputs a first initialization voltage at a first level to the display panel during an active period of the low power mode. The power supply outputs a second initialization voltage at a second level to the display panel during at least a portion of a blank period of the low power mode. The second level is higher than the first level.