According to the 2011 Census of India, the town of Diu had a population of approximately 23,991, while the entire Diu district was home to around 52,074 residents. The island has experienced steady, albeit modest, population growth, balancing natural increases with a degree of out-migration by youth seeking employment in larger Indian cities or abroad (particularly in Portugal and the UK, due to historical ties).
The population is highly literate, boasting a literacy rate of over 83%, which is higher than the national average. Ethnically and culturally, the residents are primarily of Gujarati descent. Hinduism is the dominant religion, practiced by the vast majority, followed by significant Muslim and Christian minorities. Gujarati, Hindi, and English are the most widely spoken languages, while Portuguese—once the language of administration—is now spoken by only a small, aging fraction of the population.