An optical image capturing system includes five lens elements, the five lens elements being, in order from an object side to an image side: a first lens element; a second lens element having positive refractive power; a third lens element having positive refractive power; a fourth lens element; and a fifth lens element having an image-side surface being concave in a paraxial region thereof and at least one convex critical point in an off-axis region of the image-side surface thereof.