Rikke Pedersen, 24, clocked two minutes 19.11 seconds to beat the previous mark of 2:19.59 set by American Rebecca Soni at the Olympic Games in London last year.
Images from the 15th FINA World Swimming Championships held in Barcelona on Thursday.
Russia's Yuliya Efimova followed up Friday's world championship gold medal in the women's 200 metres breaststroke by setting a world record in the 50 metres version of the event in her heat on Saturday.
Mitchell Larkin completed a rare backstroke double and Bronte Campbell won the blue riband women's 100 metres freestyle title as Australia celebrated another golden night at the world swimming championships.