An image display apparatus and a method of displaying an image are provided. The image display apparatus includes: a display; a graphics processing unit (GPU); and a processor configured to: determine a copy region of a planar-format image based on information regarding a current viewpoint, control the GPU to generate a sphere-format image by mapping an image corresponding to the copy region to a sphere and to generate an output image by rendering the sphere-format image, and control the display to display the output image.