Which African central bank began operations in 1921?

The South African Reserve Bank began operations in 1921.

It was established under the Currency and Banking Act of 1920 and opened on 30 June 1921. Its creation followed monetary disruption during and after the First World War, when South Africa sought a central institution to manage currency and banking conditions. It is commonly described as Africa's oldest central bank.

The bank's headquarters are in Pretoria. Its responsibilities include conducting monetary policy, issuing South African banknotes and coins, managing official reserves, supporting financial stability and serving as banker to the government. South Africa's constitution gives the bank a mandate to protect the value of the currency in the interest of balanced and sustainable economic growth.

The South African Reserve Bank is not the same institution as the Central Bank of Kenya or the Bank of Ghana. Those central banks were established later, in 1966 and 1957 respectively. The South African currency is the rand.