The First Sudanese Civil War (also known as Anyanya rebellion or Anyanya I, after the name of the rebels) is a conflict from 1955 to 1972 between the northern part of Sudan and a south that demands more regional autonomy.

Half a million people die over the 17 years of war, which may be divided into three stages: initial guerrilla war, Anyanya and South Sudan Liberation Movement.

However, the agreement that ends the fighting in 1972 fails to completely dispel the tensions that had originally caused the civil war, leading to a reigniting of the north-south conflict during the Second Sudanese Civil War (or Anyanya II) (1983–2005).

The period between 1955 and 2005 is thus sometimes considered to be a single conflict with an eleven-year ceasefire that separates two violent phases.