Turkish President Recep Tayyip Erdogan fired the governor of the central bank and replaced him with his deputy.
No official reason has yet been given for the sacking of Murat Cetinkaya, who had held the position since April 2016.
However, it comes amidst reports of disagreements over interest rates, which the government wants to lower in a bid to boost economic growth.
The announcement has prompted renewed concern over the central bank's independence.
President Recep Tayyip Erdogan has called for interest rates to be lowered, describing them as the "mother and father of all evil". He has claimed that high-interest rates cause inflation and believes that lowering them will improve growth.