This is Yialos (Gialos) Beach, located right in Ios Port. Further down to the right was our accommodation on the island and we passed by the beach every time we went out. Of course, we also took way too many photos and I played quite a bit in the sand. The water was cold when we visited in May 2017.
But Yialos is not the only beach close to the port. Going further and following the road, Tzamaria shows up after about 1km and after about 2km, Koumbara.