The 35-year-old congressman won by unanimous decision after a12-round fight in Las Vegas that saw him outpunch the previously unbeaten Bradley.
"We once again rejoice in the victory of Congressman Manny Pacquiao," said deputy presidential spokeswoman Abigail Valte.
"Our national fighter's strength and ability has prevailed to regain the World Boxing Organization welterweight title," she said.
Millions of Filipinos watched the fight live on cable TV, in cinemas or restaurants, while others waited for the delayed, free telecast on television at their homes.
"I'm so happy to be world champion again," Pacquiao said after the bout.
"Tim Bradley was not an easy fight.”