Disordered regions within proteins have increasingly been associated with various cellular functions. Identifying the specific roles played by disorder in these functions has proved difficult. However, the development of reliable prediction algorithms has expanded the study of disorder from a few anecdotal examples to a proteome-wide scale. Moreover, the recent omics revolution has provided the sequences of numerous organisms as well as thousands of genome-wide data sets including several types of interactomes. Here, we review the literature regarding genome-wide studies of disorder and examine how these studies give rise to new characterizations and categories of this elusive phenomenon.