Centrosomal proteins (CEPs) are active components of centrioles that mediate multiple biological processes, such as ciliogenesis and centriole biogenesis; therefore, CEP dysfunctions are broadly implicated in various human diseases. Although CEPs have been genetically linked to reproduction, the underlying molecular mechanisms remain poorly understood. Here, we report that knocking out Cep112 in mice causes male infertility with various sperm abnormalities and phenotypes consistent with human asthenoteratozoospermia. Microscopic observations revealed CEP112 is a novel component of atypical centrioles in human sperm cells. Mechanically, as an intrinsically disordered region-rich RNA-binding protein, CEP112 interacted with hnRNPA2B1 and condensed with key spermiogenesis-related mRNA molecules (Fsip2, Cfap61, and Cfap74) via liquid–liquid phase separation, which promoted RNA transport and the maintenance of local translation during spermiogenesis. Furthermore, two patients with bi-allelic variants in CEP112 were identified in a cohort of 568 unrelated infertile men, and in vitro experiments showed the mutations affected the phase-separation characteristics. Our findings provide new information on the roles of CEP112 and LLPS in male reproductive biology.