The yuan, also known as the renminbi, will join the US dollar, euro, Japanese yen and British pound next year in the basket of currencies the IMF uses as an international reserve asset.
IMF Managing Director Christine Lagarde called the decision "an important milestone in the integration of the Chinese economy into the global financial system."
"It is also a recognition of the progress that the Chinese authorities have made in the past years in reforming China's monetary and financial systems."
China, the world's second-largest economy, asked last year for the yuan to be added to the Special Drawing Rights basket, but until recently it was considered too tightly controlled to qualify. The yuan already had met the IMF's criteria for being widely used.
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The board approval had been widely expected after IMF staff experts earlier in November said that Chinese authorities had taken the steps necessary for the yuan to be called "freely usable", and Lagarde endorsed their recommendation.
"The continuation and deepening of these efforts will bring about a more robust international monetary and financial system, which in turn will support the growth and stability of China and the global economy," she said.
IMF members can use the Special Drawing Rights basket to obtain currencies to meet balance-of-payments needs. The Fund also issues its crisis loans -- crucial to struggling economies like Greece -- valued in SDRs.
The yuan's entry into the basket takes effect on October 1, 2016.