Voluntary taxation is a theory that states that taxation should be a voluntary act. Under the theory, people should have the option to pay taxes instead of being forced to pay taxes by their government. Under this theory, the people would control how much they pay and where they spend it. The theory is a part of Objectivist politics and many libertarian ideologies. Proponents of some studies assert that individuals will give to government, paying voluntary taxes to support specific functions.

In one study, subjects were each given $20 to be anonymously allocated between themselves and a charitable organization their discretion (repeated for 12 different organizations, $240 total/subject), voluntary donations for each organization averaged 22% to government organizations and 27% to private nonprofits, and were influenced by their cause, level, and perceptions of effectiveness and efficiency (on average, 76% of the endowment was kept by the subjects). State lotteries are an example of a voluntary taxation system.