The IOC has further approved a plan for North and South to field a unified women's hockey team, Olympic chief Thomas Bach told reporters following a meeting in Lausanne with sport and government officials from the two countries.
The announcement from Bach marked the approval of a landmark deal between the two Koreas that has eased tensions building for months.
The 22 athletes will compete in three sports and a total of five disciplines, including figure skating, short-track speed skating, cross-country skiing and Alpine skiing, in addition to hockey.
North Korea will also send 24 officials and 21 media representatives to the Games in Pyeongchang, which start on February 9.
At the opening ceremony, the joint delegation "will be led into the Olympic stadium by the Korean unification flag" carried together by an athlete from each country, the IOC said. A special unity uniform will be created for the event.
"Today marks a milestone on a long journey," Bach said after the meeting, which finalised details previously agreed between the two countries. "The Olympic Winter Games in Pyeongchang are hopefully opening the door to a brighter future on the Korean peninsula, and inviting the world to join in a celebration of hope."
North and South Korea remain technically at war since the Korean war ended with armistice, not a peace treaty, in 1953.
The North's decision to compete in Pyeongchang -- just 80 kilometres south of the demilitarised zone that divides the Koreas -- is an historic diplomatic coup, especially after months that saw nuclear and missile tensions surge to new heights.