A fiscal year (or financial year, or sometimes budget year) is a period used for calculating annual ("yearly") financial statements in businesses and other organizations. In many jurisdictions, regulatory laws regarding accounting and taxation require such reports once per twelve months, but do not require that the period reported on constitutes a calendar year (i.e., January through December). Fiscal years vary between businesses and countries.

In addition, many companies find that it is convenient for purposes of comparison and for accurate stock taking to always end their fiscal year on the same day of the week, where local legislation permits. Thus some fiscal years will have 52 weeks and others 53. Major corporations that adopt this approach include Cisco Systems and Tesco.

In the United Kingdom, a number of major corporations that were once government owned, such as BT Group and the National Grid, continue to use the government's financial year, which ends on the last day of March, as they have found no reason to change since privatisation.

Nevertheless, the fiscal year is identical to the calendar year for about 65% of publicly traded companies in the United States and for a majority of large corporations in the UK and elsewhere (with notable exceptions Australia, New Zealand and Japan).

Many universities have a fiscal year which ends during the summer, both to align the fiscal year with the school year, and because the school is normally less busy during the summer months. In the Northern hemisphere this is July in one year to June in the next year. In the southern hemisphere this is January to December of a single calendar year.

Some media/communication based organizations use a Broadcast calendar as the basis for their fiscal year.