<p>The Colobinae (leaf-eating monkeys) are a major group of catarrhine primates, a clade that also includes their sister subfamily the Cercopithecinae (cheek-pouch monkeys) and the Hominoidea (apes and humans). Among catarrhines, colobine monkeys are ecologically distinct and are represented by a diverse modern radiation; they also have an extensive fossil record from the late Middle Miocene onwards. However, interpreting their diversity and biogeography is hampered significantly by the near absence of reliable phylogenetic hypotheses for the clade. To address this gap, the relationships of the fossil and extant colobines are estimated with total evidence parsimony and Bayesian phylogenetic analyses. Topologies inferred by these analyses differ slightly but are largely congruent, clarifying the stem versus crown position of several species and identifying taxa that are likely polyphyletic with respect to their current generic assignments (denoted here with quotation marks around the generic nomen). Several Late Miocene taxa (including <i>Microcolobus tugenensis</i>, <i>Sawecolobus lukeinoensis</i>, <i>“Cercopithecoides” bruneti</i>, <i>“Paracolobus” enkorikae</i>, <i>Libypithecus markgrafi</i>, <i>Mesopithecus pentelicus</i>, and <i>“Cercopithecoides” kerioensis</i>) along with some later-occurring Plio-Pleistocene taxa (<i>Rhinocolobus turkanaensis</i>, <i>“Paracolobus” mutiwa</i>, and <i>Dolichopithecus ruscinensis</i>) are identified as stem colobines. Several species of <i>Cercopithecoides</i> are crown African colobines, and the Asian Pliocene taxa <i>Parapresbytis eohanuman</i> and <i>Kanagawapithecus leptopostorbitalis</i> are consistently recovered with modern Asian colobines. These results support several inferences about their historical biogeography, ecological evolution, and the evolution of the colobine craniodental morphotype, with implications for understanding the polarity of ecological and morphological features within the cercopithecoids and catarrhines more broadly.</p>