If you want to go with your dog in the south of Corsica, the perfect destination is Porto-Vecchio. With its heavenly beaches, the seaside resort allows dogs on the beaches provided they are on leash.
In the Gulf of Ajaccio, the small seaside resort of Propriano in the Gulf of Valinco welcomes them.
There are also dog friendly beaches in the Gulf of Porto but access is more difficult and the beaches less beautiful.
To have more choice, you will have to go on the beaches of North Corsica where pets are allowed on most beaches.