South Korean President Moon Jae-in and Ivanka Trump, the daughter of US President Donald Trump were in the stadium, as was General Kim Yong Chol, head of the North Korean delegation.
The Games opened on February 9 and were the biggest Winter Olympics of all time, with 2,920 athletes competing for a record 102 gold medals.
Norway topped the final medal tally with 14 golds ahead of Germany, which also had 14 gold but fewer medals in all. Canada was third with 11 golds. Hosts South Korea were seventh.
The run-up to the Games sparked an abrupt thaw in relations between North and South Korea, with the North sending a delegation of more than 500 to Pyeongchang, including 22 athletes.
Russian athletes were to march into the closing ceremony under a neutral flag after a ban on Russia's Olympic committee was upheld on Sunday following a mass doping scandal.