The Occitano-Romance languages consist of Occitan, Catalan, and Gascon. They are spoken in southern France, eastern Spain, Andorra, Monaco, and some parts of Italy. Some people consider Catalan and/or Gascon to simply be other varieties of Occitan.
The Occitano-Romance language spoken furthest to the south is, of course, Catalan, which can be roughly split into Western Catalan and Eastern Catalan varieties. The southernmost variety of Catalan is Valencian, a variety of Western Catalan. The other variety of Western Catalan is Northwestern Catalan, spoken to the north of Valencian. The two varieties of Eastern Catalan are Central Catalan, spoken to the east of Northwestern Catalan, and Northern Catalan, spoken in Roussillon, France, and just across the border in Spain. Balearic is spoken in the Balearic Islands, and Algherese is spoken in Alghero, northwestern Sardinia.
Gascon is spoken in southwestern France, to the north of the areas where Catalan is spoken, and Lengadocian, a variety of Occitan, in southern France (to the east of Gascony). Provençal, another variety of Occitan, is spoken to the east of Lengadocian. Two varieties are spoken to the immediately north of Lengadocian: Limousin to the west and Auvergnat to the east. Finally, the Vivaro-Alpine variety is spoken to the east of Auvergnat and north of Provençal.