The funeral Mass in Rome was telecast live to churches around the world from Paris's famed Notre Dame Cathedral to a seaside park in Manila.
"He has had a huge impact on us, we are the generation of John Paul II," said Florence de la Rousserie, 27, one of 7,000 worshippers who filled Notre Dame. "He has taught us all the rules of Christian morality, of spirituality. I am moved. I am sorry."
"He was a Pope for humanity," said Assemian Omer Alain, 40, from Ivory Coast who was one of about 500 people at Sacred Heart basilica overlooking Paris from the hill of Montmartre. "He was a phenomenon."
About 800,000 people gathered in a vast field in Krakow, Poland, where the Pope was once archbishop, to follow the funeral on a giant screen. Schools and businesses closed across the country as Poland mourned its national hero.
Television screens also were set up in churches across Africa.
In the residential districts of Congo's capital, Kinshasa, choir music floated from open windows of homes where many residents tuned TVs and radios to the event in Rome.
Flags flew at half-mast in the civil war-torn Ivory Coast.
The government closed its offices and asked people to observe the day of mourning.
In Moscow, hundreds of people filled the Roman Catholic Cathedral of the Immaculate Conception. "I am Orthodox, but I am here today and not for the first time. The Pope is a figure for whom I have great respect and interest. I liked his idea of unifying the churches," said Nadezhda Chekhova, a teacher.
John Paul was credited with trying to heal rifts between the Roman Catholic Church and the Orthodox Church, but he never made it to Russia.
Spanish and Vatican flags with black ribbons hung from balconies and shops in the capital Madrid.
Several thousand Slovaks gathered for an open-air Mass in a Bratislava suburb in the same spot where the Pontiff celebrated a Mass for 200,000 faithful during his last trip there in 2003.
In London's cold, rainy Trafalgar Square, about 200 people watched a giant screen showing coverage of the funeral.
"I tried to get to Italy and get to Rome, but there were no hotels available and hardly any flights," said Maria Szczepankiewicz, 49, of north London, whose father emigrated from Poland. "I didn't want to be at home watching the funeral, I wanted to be with other people to get some kind of feeling."
Because of the time difference from Rome, the service was held before dawn in the Americas, but mourners still streamed into churches.
In Los Angeles, dozens gazed at a television at Our Lady of the Bright Mount Church, home to a mostly Polish congregation.
"We're sad and we are happy because now we know he is in heaven," said Stan Czerwinski, 49.
In Canada, about 2,000 people attended an outdoor Mass in the darkness near a statue of Pope John Paul II northwest of Toronto.
Throughout Asia, Muslims, Buddhists, Hindus and Sikhs joined Catholics in church services and prayers.
In Tokyo, the Tibetan spiritual leader, the Dalai Lama, urged people to continue the late Pontiff's legacy of peace.
"Firstly, we lost a great human being, a leader of a great religion," he said. "Now it is important that we must carry all his messages and guidance with us. We must make every effort to fulfil his wishes."
Some 1,500 Japanese packed a memorial Mass at St Mary's Cathedral, some spilling outside under the blazing sun.
In the Philippines, Manila Archbishop Gaudencio Rosales called the gathering of the faithful in Asia's most populous Catholic nation a "celebration of life" for John Paul.
In mainly Buddhist Sri Lanka, where the Pope visited in 1995, private TV station ART interrupted regular programming to broadcast the funeral live after receiving hundreds of phoned requests.
Some 14,000 people packed into a cricket ground in Adelaide for a memorial service for the Pontiff, who last year criticised Australia for its secular trends and warned that attending Mass on Sunday should not be subordinate in a "weekend dominated by such things as entertainment and sport".