Santorini is a volcano, and its beaches show it. There is no white sand or shallow turquoise lagoon here — the shores are black, red or grey volcanic sand and pebble, the water often deepens fast, and on most of them the scenery is the main event rather than the swimming. The long organized strips sit on the gentler southeast coast: black-sand Kamari under the Mesa Vouno cliff, and the beach-club stretch of Perivolos and Black Beach toward Perissa. The south and southwest hold the photogenic volcanic coves — Red Beach, the lunar Vlychada, and quieter Mesa Pigadia, White Beach and Gialos near Akrotiri. Browse every verified beach on the island in Santorini.
This is a curated best-of rather than the full list. If you want comfort and a full day in the sun, head for the organized southeast; if you want the dramatic volcanic colours, come for the coves and treat the swim as a bonus. A car or scooter makes the south and southwest far easier — some of the best coves sit at the end of a rough track. Pick a coast below, then check each beach page for access detail before you go.