In the United States, Tax Day is a colloquial term for the day on which individual income tax returns are due to the federal government. The term may also refer to the same day for states, even where the tax return due date is a different day.

Since 1955, Tax Day is usually on April 15. When April 15 falls on a weekend, Emancipation Day, or any other holiday, tax returns are instead due on the following business day.