A planographic printing plate precursor comprising: a substrate; a photosensitive layer disposed on the substrate, the photosensitive layer including a light-to-heat conversion agent and a compound, which is at least one of crosslinkable and polymerizable, with solubility of the photosensitive layer in an alkali developing solution being decreased by the effect of at least one of light and heat; and an overcoat layer including a polymer, which is hydrophobic and soluble in an aqueous alkali solution.