A luxury tax is a tax on luxury goods: products not considered essential. A luxury tax may be modeled after a sales tax or VAT, charged as a percentage on all items of particular classes, except that it mainly directly affects the wealthy because the wealthy are the most likely to buy luxuries such as expensive cars, jewelry, etc. It may also be applied only to purchases over a certain amount; for instance, some U.S. states charge luxury tax on real estate transactions over a certain limit.

A luxury good may be a Veblen good, which is a type of good for which demand increases as price increases. Therefore, the effect of a luxury tax may be to increase demand for certain luxury goods. In general, however, since a luxury good has a high income elasticity of demand by definition, both the income effect and substitution effect will decrease demand sharply as the tax rises.