Fee simple is an ownership interest in real property that is the most full, unlimited, and absolute property interest recognized by law. This ownership interest of title in fee simple is also referred to as fee simple absolute; estate in fee simple; fee simple title; or simply fee, and the term is usually used to indicate the real property ownership interest a seller is transferring to a buyer.

The rights of a fee simple property owner are limited by the government’s power to tax the land (property taxes) and to purchase the land through the compulsory process mandated by state law—often as provided in the state’s constitution or in the state’s statutes—which is known as eminent domain.

In limited circumstances fee simple ownership may also be subject to the state’s police powers, the law of escheat (when the property owner dies without a will and without heirs), and encumbrances or deed restrictions on the use of the land.

In Oregon, fee simple ownership represents the most complete form of ownership in real estate, granting the holder full rights to the property, subject to certain limitations. The owner of a fee simple estate has the right to use, sell, lease, or bequeath the property as they see fit. However, these rights are not without restrictions. The government retains the power to levy property taxes on the land, and through eminent domain, it may compel the sale of the property for public use, provided that just compensation is given, as outlined in both the United States Constitution and Oregon state law. Additionally, the state's police powers may impose regulations for the general welfare, such as zoning laws. If a property owner passes away intestate (without a will) and without heirs, the property may escheat, or revert, to the state. Lastly, fee simple ownership may be subject to encumbrances or deed restrictions, which can limit how the property is used. These legal frameworks ensure that while fee simple provides extensive property rights, they are exercised within the bounds of broader societal and governmental interests.