Cross-cultural studies of religion have consistently treated ancestor worship as a specific, narrow practice that is found in many traditional societies but far from all of them. In contrast, Steadman, Palmer, and Tilley (1996) have proclaimed that ancestor worship was a universal behavior in traditional, small-scale societies and that the practice is found in societies where it was previously thought to be absent. In this paper, we describe one such society, the Iban, whose religious practices are often claimed to not include the worship of ancestors, despite ancestors being central to their religion. We demonstrate that many of the gods and spirits of the Iban supernatural pantheon are most clearly understood as ancestors. Furthermore, we argue that the Iban example may not be an outlier, and that ancestor worship may be prevalent in many more societies than previously claimed. We end by describing the weaknesses of some of the common reasons used to downplay the ubiquity of the practice in previous ethnographic treatments and cross-cultural studies.