There's a laundry called Rosy, which is on the beach side just after the main supermarket Supersol on the road going out of Estepona towards Marbella, Carole.

I don't know of any laundromats in the area, although I've often thought it would be worth setting up in one of the marinas, where you see people who live on the yachts handwashing their clothes wishing there was such a facility.