The bicycling monarch who broke with convention by shopping at her local supermarket and sending her children to state school died of a lung infection at 5:50 a.m. (0450 GMT) in the Soestdijk palace where she lived most of her life. She had been ill for several years.
Her husband, Prince Bernhard, and three of her four daughters, including Queen Beatrix, were at her bedside when she died. The fourth daughter arrived soon afterwards from the United States.
"The Netherlands has lost its mother," Prime Minister Jan Peter Balkenende said in a televised address.
He said Juliana, who reigned from 1948 until she abdicated in 1980 in favor of Beatrix, was a queen "for the people, not the powerful." Balkenende said she would have become a social worker if she had not been queen.
Juliana Louise Emma Marie Wilhelmina was born in the Hague, the only child of Queen Wilhelmina and Prince Hendrik.
On ascending the throne, she quickly captured hearts at home and abroad as she strove to bring the royal family closer to the people. It is her birthday, on April 30, that is still celebrated as the Queen's Day holiday.
"Together with Prince Bernhard, she worked for the reconstruction of our country after World War II. Supported by her religion, she was an indefatigable campaigner for solidarity, community spirit and human dignity," the prime minister said.