Ancestry is a central concept in human population genetics, yet remains undertheorized in philosophy of biology. This Element examines ancestry through the lens of scientific objectivity, asking whether it can function as an objective concept. It begins by distinguishing the meanings of ancestry and showing the concept's ambiguity and imprecision. It then considers how ancestry relates to population descriptors such as race and ethnicity, focusing on virtues often attributed to it, including neutrality, measurability, simplicity, generality, and correspondence. The core question is what kind of objectivity ancestry can claim. The Element argues that ancestry's objectivity is constitutive: a vague concept becomes an object of inquiry only once the relevant practices, assumptions, and research aims are specified. Establishing the objectivity of ancestry therefore requires examining scientific practices in human population genetics. The Element concludes that ancestry is an iterative, model-dependent, context-sensitive construct that nonetheless plays an important role in scientific inquiry.