Sanibel is an island and city in Lee County, Florida, United States. The population was 6,382 at the 2020 census. It is part of the Cape Coral-Fort Myers, Florida Metropolitan Statistical Area.

As of early 2026, the estimated permanent population of Sanibel Island is approximately 6,342 people. This figure shows that the community has largely stabilized following the significant population fluctuations caused by Hurricane Ian in late 2022. While the 2020 census recorded 6,382 residents, the island saw a temporary dip as homes were rebuilt and infrastructure was restored. Today, the population remains heavily skewed toward retirees, with a median age of about 67 years. Despite being a major tourist destination that sees tens of thousands of visitors during the "winter season," the city government of Sanibel remains committed to strict density limits and environmental preservation to ensure the island maintains its "small-town" feel and sanctuary status. In 2026, the housing market is primarily owner-occupied (over 90%), and the community has successfully transitioned back to its full residential capacity, with nearly all major resorts and local businesses fully reopened to support both the permanent residents and the seasonal influx of "snowbirds" and vacationers.