This is an incomplete list of rivers that are at least partially in Spain. The rivers flowing into the sea are sorted along the coast. Rivers flowing into other rivers are listed by the rivers they flow into. Rivers in the mainland Iberian Peninsula can be divided into those belonging to the Mediterranean watershed, those flowing into the Atlantic Ocean and those emptying into the Cantabrian sea (a marginal sea of the Atlantic off the northern coast of the Iberian peninsula).
Tributaries are listed down the page in an downstream direction. The main stem river of a catchment is labelled as ms, left-bank tributaries are indicated by l, right-bank tributaries by r. Where a named river derives from the confluence of two differently named rivers these are labelled as ls and rs for the left and right forks (the rivers on the left and right, relative to an observer facing downstream). The transboundary rivers partially running through Portugal or France and/or along the borders of Spain with those countries are labelled as int.
The list begins with the northernmost item of the Mediterranean watershed (close to the French border) and moves clockwise around the Iberian Peninsula.
Outside from the Iberian peninsula mainland, streams in the Canary Islands, the Balearic Islands, Ceuta and Melilla are seasonal watercourses. The Santa Eulàlia river in Ibiza was traditionally considered as the single proper 'river' in the Balearic Islands, but it lost its constant flow by the late 20th-century.
This includes the basins emptying in the Mediterranean Sea located in the coastline north from the Ebro. It has to be noted this leaves out the Garonne and the Ebro, both draining parts of Inner Catalonia, as well as small streams in Catalonia emptying in the Mediterranean south from the Ebro.
This roughly includes the basins emptying in the Mediterranean Sea ranging from those emptying south from the Ebro to the intermittent seasonal watercourses characteristic of the areas near the border between Murcia and the Andalusian province of Almería.
This section features the rivers flowing into the Atlantic Ocean, ranging from the Punta de Tarifa (the meeting point of the Mediterranean and the Atlantic) to the Punta de Estaca de Bares (the conventional boundary between the Atlantic of the Cantabrian Sea, one of the former's marginal seas).
This includes the rivers flowing into the Cantabrian Sea (as well as in the case of the Garonne the wider Bay of Biscay) east of the Punta de Estaca de Bares. They are chiefly short streams streaming down the Cantabrian Mountains and the southern slopes of the Pyrenees.