Fishes have evolved extraordinary morphological and sensory adaptations to best utilize their natural habitats and expand their ranges. Due to the large variability among habitats and geographic regions, an examination of the mechanisms that influence and regulate feeding mechanisms and sensory systems is essential to understanding the distribution of taxa across space and time. In particular, an examination of the feeding capabilities of diverse clades of fishes will elucidate the role of these functional traits on the range size and distribution of lineages. The overarching goal of this thesis was to explore the phylogenetics, evolution and biogeography of the goatfishes, with a focus on the unique foraging behavior associated with substrate preferences and barbel use. In Chapter 2, I explore the evolution of the goatfishes through inference of the most species rich time-calibrated phylogeny of the goatfishes to date. This phylogeny was inferred using a robust genomic dataset and is used as the basis for all evolutionary analyses used throughout this thesis and reveals novel aspects of goatfish evolution that were previously unknown. In Chapter 3, I examine the global biogeographic distribution and assemblage structure of the goatfishes using bioregionalization approaches. The boundaries between these bioregions are specific to the goatfishes and highlight global patterns of species turnover and the locations of potential barriers to dispersal. In Chapter 4, I test hypotheses about the ecomorphological relationship between head and body shape with preferential foraging on different substrate types across the goatfishes using a robust geometric morphometric dataset. I find evidence that preferential foraging on hard substrate evolved relatively recently, and is associated with changes to forehead shape, elongation ratio, and head length. This dissertation represents a major advance in the integrative examination of the evolutionary relationships, assemblage patterns, and ecomorphological associations across the goatfishes. The results of this thesis provide a comprehensive examination of the many unique characteristics associated with the goatfishes, provides the phylogenetic framework required to fully understand the biology of this family, and enables us to begin addressing questions about how future changes in reef ecosystem health will impact the biology of this clade.