Sen. Hillary Rodham Clinton has not won a nominating contest since Super Tuesday, more than two weeks ago.
More than 20,000 U.S. citizens living abroad voted in the primary, which ran from Feb. 5 to Feb. 12. Obama won about 65 percent of the vote, according to the results released Thursday.
Voters living in 164 countries cast votes online, while expatriates voted in person in more than 30 countries, at hotels in Australia and Costa Rica, at a pub in Ireland and at a Starbucks in Thailand. The results took about a week to tabulate as local committees around the globe gathered ballots.
"This really gives Americans an opportunity to participate," said Christine Schon Marques, the international chair of Democrats Abroad.
Italian Sports Minister Giovanna Melandri, who has dual citizenship, cast a vote for Obama in Rome.
"It wasn't an easy choice for me. I would still love seeing a ticket with Obama and Hillary," Melandri told The Associated Press in a telephone interview. "A drive for change is what is needed in the U.S. and I think that Obama has that drive."
There is no comparable primary among Republicans, though the GOP has several contests this weekend in U.S. territories, including party caucuses in Puerto Rico Sunday.
The Democrats Abroad controls seven pledged delegates at the party's national convention this summer. However, the group's system of dividing the delegates is unique, and could create an anomaly in which Obama and Clinton end up with fractions of delegates.
The party will send 14 pledged delegates to the convention, each with a half vote. The primary was used to determine nine people, or the equivalent of 4.5 delegates. Obama won 2.5 and Clinton won two, according to Schon Marques.
The Democrats Abroad will hold a global convention in Vancouver, Canada, in April to select the other five people who will attend the convention. They will represent the remaining 2.5 votes.
The system creates the possibility that Obama and Clinton could each end up with a fraction of a delegate at the convention, Schon Marques said.
Democratic parties in U.S. territories use similar systems, in which they send twice the number of delegates, giving them each a half vote. But their systems are designed to ensure that that candidates do not end up with fractions of delegates.
Stacie Paxton, a spokeswoman for the Democratic National Committee, said party rules allow for delegates with a half vote so that more people can attend the convention from far-flung places.
Obama's delegate total, which includes new superdelegate endorsements, increased to 1,358.5 Thursday. Clinton was at 1,264.
It will take 2,025 delegates to claim the nomination at this summer's convention.
