A wealth tax (also called a capital tax or equity tax) is a tax on an entity's holdings of assets. This includes the total value of personal assets, including cash, bank deposits, real estate, assets in insurance and pension plans, ownership of unincorporated businesses, financial securities, and personal trusts (a one-off levy on wealth is a capital levy). Typically, liabilities (primarily mortgages and other loans) are deducted from an individual's wealth, hence it is sometimes called a net wealth tax.

As of 2017, five of the 36 OECD countries had a personal wealth tax (down from 12 in 1990).

Proponents note that it can reduce income inequality by reducing the accumulation of large amounts of wealth by individuals. Critics note that a wealth tax can cause wealthy entrepreneurs and businesspeople to leave the country and move their wealth to a more tax friendly nation.