The newest addition to the Swedish royal family was born at 10:41 pm local time, Marshal of the Realm, Svante Lindqvist, announced on the Royal Court's website. Princess Madeleine's husband, Christopher O'Neill, was present during the birth at the New York Presbyterian Weill Cornell Medical Center.
King Carl XVI Gustaf and Queen Silvia are in Stockholm and have been informed. Royal spokeswoman Annika Sönnerberg said that mother and baby are both doing well, although the child arrived a few days earlier than expected.
The Swedish prime minister, Fredrik Reinfeldt, sent his congratulations to the princess and Mr O'Neill, saying: "It is a great day for the royal family and for the new parents. There are many today who share the joy of Princess Madeleine and Christopher O'Neill."
A Te Deum service of thanks will be held on March 2nd in the church of the Royal Palace, the Slottskyrkan in Stockholm.
Royal expert Roger Lundgren told news agency TT that it is not yet known what titles the child will hold.
Crown Princess Victoria's infant daughter Estelle is currently in line to one day be queen. Historian Dick Harrison said the new baby will be fifth in line to the throne, after Victoria, Estelle, Prince Carl Philip and Madeleine.
However, in order for Princess Madeleine and Christopher O'Neill's child to become a regent, it would have to become a Swedish citizen, grow up in Sweden, be a protestant and not marry without the consent of the king and government.
Christopher O'Neill was born in London, holds a British passport and is of the Catholic faith.