The Magdalena River is the principal river of Colombia, running about 1,540 kilometres (950 miles) from South to North through the western half of the country. It is navigable through much of its lower reaches.

Its headwaters are in the South of the country, where the Andean subranges Cordillera Central and Cordillera Oriental separate, in Huila department. The river then runs east of north in a great valley between the two cordilleras. It reaches the coastal plain at about nine degrees north, then runs east for about 100 kilometres, then north again, reaching the Caribbean Sea at the city of Barranquilla.