The 30-year-old returned to the Swedish capital from New York, where she met Mr O'Neill two years ago.
Some 500 guests were invited to the ceremony at the Royal Chapel in Stockholm.
Sweden's royal family enjoys wide public support and the ceremony was broadcast live on state TV.
Princess Madeleine's elder sister, Crown Princess Victoria, married her personal trainer Daniel Wesling in Stockholm three years ago. But Saturday's wedding was not considered as big an occasion.
In June 2010, the whole of the Swedish capital was transformed for the celebrations.
Along with representatives from many European royal families present for Princess Madeleine's wedding, John Taylor of UK pop group Duran Duran was among the guests.
The couple tied the knot in a ceremony that was part in Swedish and part in English. They then travelled in a horse and carriage procession through the city centre. (+ BBC video) » | Saturday, June 08, 2013
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