A motion estimation apparatus and method for estimating a global motion vector of an image due to hand trembling by using zoom information and focus information are provided. The motion estimation method includes: dividing a photographed image into a plurality of image blocks; determining a weight value for a motion vector of each of a plurality of image blocks based on focus information and zoom magnification information; predicting a motion vector for each image block; and estimating a global motion by applying the weight value determined for the motion vector for each image block to the predicted motion vector.