The article discusses the nature and analyzes the features of fee simple absolute as a key, fundamental title in the system of real property law in the United States. It is noted that this title is the closest to continental (incl. Russian) proprietary structures. The author examines the characteristics of this title: its potentially infinite duration, alienability, completeness of powers given to the owner, the absence of encumbrances, etc. The article explores the requirements on the use of certain reservations and phraseological units in agreements and unilateral contracts, on the basis of which property is transferred due to the fee simple absolute. The author examines controversial provisions of the doctrine, legislation and case practice of the United States that define the principles of application of the rules on fee simple absolute. Particular attention is given to the special statutory rules, which contribute to the interpretation of the party's intent to transfer ownership based on fee simple absolute and/or to obtain such a right. In conclusion, the author summarizes the analysis of the Anglo-American approach to defining fee simple absolute as a subjective civil right, as well as evaluates the risks of artificial delineation of property rights and objects which these rights can be applied to.