An object of the invention is to provide a laser illuminating device and an image display device that enable to remove speckle noises in a diffraction field and an image field, uniformly illuminate an illumination plane, and realize miniaturization. A laser illuminating device 100 includes a laser light source 3, a first lens 1 including a plurality of microlenses 10 each having a predetermined numerical aperture in an in-plane direction, each of the microlenses 10 being adapted to expand laser light emitted from the laser light source 3 to thereby superimpose the laser light transmitted through each of the microlenses 10; and a second lens 2 having an effective diameter larger than an effective diameter of the first lens 1, and for compensating for a divergence angle of the laser light expanded by each of the plurality of the microlenses 10.