The Riverlands is one of the constituent regions of the Seven Kingdoms. They have been a frequent battleground in the civil wars that have afflicted the Seven Kingdoms and also in the wars that took place between the old nations of the continent before the Targaryen Conquest. During the time of the First Men, the Riverlands were an independent kingdom known as the Kingdom of the River and the Hills. Located roughly in the center of the continent, and with few geographical boundaries such as mountains, for centuries it has been a borderland between surrounding strong kingdoms. The Riverlands were ruled by the Ironborn at the time of the Targaryen Conquest, and Aegon the Conqueror's assault was assisted by a popular uprising led by House Tully. For this reason, the Riverlands didn't have a king at the time of the invasion, and the Riverlands are not technically counted as one of the "Seven" Kingdoms. However, for administrative purposes, the Riverlands and their rulers are equal to any other region of the realm. Bastards born in the Riverlands are given the surname Rivers.

During the War of the Five Kings, the riverlords hailed Robb Stark, who was the grandson of Hoster Tully through his mother Catelyn, as their King in the North. However, Robb, Edmure Tully, and their bannermen were betrayed at the Red Wedding by two of their own bannermen: Roose Bolton and Walder Frey. House Frey was then elevated to rule over the Riverlands, however, the Freys were actively opposed by many of the riverlords, including Ser Brynden Tully who managed to retake Riverrun though eventually lost it when a Lannister host arrived to assist the Freys in their siege of Riverrun. House Frey were eventually assassinated by Arya Stark in retribution for their treachery, leaving the Riverlands in disarray and their political status ambiguous. The ensuing power vacuum eventually allowed the Tullys to regain control over the Riverlands, and by the time of the Great Council of 305 AC, Edmure had reclaimed his rightful position as Lord of Riverrun. Edmure’s nephew Bran Stark was then elected as the new King of the Six Kingdoms, with his niece Queen Sansa Stark reclaiming independence in the North.

The Riverlands are dominated by the watershed of the Trident River, so-called because of its three major tributaries - the Green Fork, the Blue Fork and the Red Fork. The Green Fork is the northernmost, running north-to-south almost up to the Neck near the entrance to the Stark-held North. The Green Fork is only traversable via the castle-bridge complex known as The Twins ruled by House Frey. Thus, large armies attempting to move into or out of the North are faced with only two, predictable choices: travel along the Kingsroad as it crosses the Ruby Ford to the east, or cross the Green Fork at the Twins to the west, which requires paying an often steep toll to House Frey. The Blue Fork is south of the Green Fork, and terminates near Seagard. The Red Fork is the southernmost and winds its way through the heart of the Riverlands, between the Red Fork and the Gods Eye lake further south. After it passes Riverrun castle, the capital of the Riverlands, the Red Fork passes further to the south and west until it reaches the borders of the Westerlands.

Notable places shown in the series are: