The black and white male pup will come from the same Texas kennel whereMassachusetts Sen. Ted Kennedy's family got several of its dogs, according to the Web site TMZ.
The pooch, originally named "Charlie" was reportedly returned to the kennel by its first owners.
Kennedy, whose dogs Sunny and Splash are often by his side, endorsed Obama during the Democratic primary.
"We couldn't be happier to see the joy that Bo is bringing to Malia and Sasha," Kennedy said in a statement. "We love our Portuguese water dogs and know that the girls - and their parents - will love theirs, too."
Bo has black fur, a white chest, white paws and a white goatee.
Several weeks ago, the Obamas had a secret get-acquainted session with the dog at the White House, the Post reported.
"He sat when the girls sat, stood when the girls stood. He made no toileting errors and did not gnaw on the furniture," the newspaper reported.
During the campaign, the Obamas promised their two girls a dog, win or lose. For weeks, the First Family was in serious negotiations over names.
"Frank was one of them. Moose was another," Michelle Obama told People magazine with a laugh and a roll of her eyes. "I'm like, no. Come on. Let's work with the names a little bit."
The Obamas have played coy with the press about the dog, appearing amused by the intense interest.
"Oh, man, now, that's top secret," the President joked Friday to reporters.
The Obamas - first-time dog owners - were attracted to the Portuguese Water Dog as a breed because the canines won't stir Malia's allergies.