Abstract: A floating solar heater for swimming pools is disclosed which includes a top cover, a vertical outer side wall with inclined inner side wall segments connected thereto, an outside rim and a bottom wall. The inner side wall segments are octagonal, coated with light reflective material, and aid in reflecting the sun's rays to heat the space inside the walls formed by the cover which dead air space also provides for floatation of the heater. The bottom wall is heated by direct sun inpingement and by the air in contact with it and is formed of a material having high heat conductivity.