This chapter is concerned with the veto power that chief executives wield over the legislative process. Along with proposal power, the veto is the main tool that executives have as legislators. In its most traditional forms, it allows presidents to block Congress, but it does not enable them to substitute the bills with their own preferences. Depending on the country, presidents may have additional roles in the legislative arena like introducing bills, calling legislatures for special or extraordinary sessions, or issuing decrees that have the power of laws. We look into veto power broadly, beyond presidential systems, which is where they are most common, and where most of the literature has developed. We also pay attention to different types of vetoes because the literature has shown that they vary in their effects and implications.