Understanding Language Outcomes in Cleft (UnLOC) is a program of research that explores why language outcomes vary among people born with cleft lip and/or palate and how these outcomes change across the lifespan. The programme investigates the complex interplay of biological, clinical, cognitive and environmental influences on language development, and examines how language relates to other key outcomes such as speech, education, social participation and quality of life. By understanding these relationships, UnLOC aims to generate evidence that will improve support, interventions and long-term outcomes for individuals born with cleft.