在微观经济学、博弈论、决策论中，预期效用假说（英文：Expected utility hypothesis），又称预期效用理论（英语：Expected Utility Theory），或期望效用理论，是一个效用理论，指在风险情况下，个人所作出的选择是追求某一数量的期望值的最大化。这个理论最早在1738年由丹尼尔·伯努利提出，该假说用于解释赌博和保险中的期望值。

冯·纽曼-摩根斯坦效用定理（Von Neumann–Morgenstern utility theorem）提出，在预期效用假说成立的前提下，一个有理性的人应该如何选择的公式。

In economics, game theory, and decision theory the expected utility hypothesis is a hypothesis concerning people's preferences with regard to choices that have uncertain outcomes (gambles). This hypothesis states that if specific axioms are satisfied, the subjective value associated with an individual's gamble is the statistical expectation of that individual's valuations of the outcomes of that gamble. This hypothesis has proved useful to explain some popular choices that seem to contradict the expected value criterion (which takes into account only the sizes of the payouts and the probabilities of occurrence), such as occur in the contexts of gambling and insurance. Daniel Bernoulli initiated this hypothesis in 1738. Until the mid-twentieth century, the standard term for the expected utility was the moral expectation, contrasted with "mathematical expectation" for the expected value.