The multi-division world champion, who is a senator in his native Philippines, has already announced his intention to run for president in the country’s 2022 elections.
The 42-year-old’s final fight was a defeat by Cuba’s Yordenis Ugas in Las Vegas last month.
“I just heard the final bell. Boxing is over,” said Pacquiao.
In a video posted on social media, Pacquiao described retiring as the “hardest decision” of his life, adding boxing had given him “the chance to fight my way out of poverty” and “the courage to change more lives”.
“I will never forget what I have done and accomplished in my life,” he said. After growing up in poverty in the south of the Philippines, Pacquiao moved to the capital Manila as a teenager to start a boxing career that would make him one of the world’s most highly paid athletes. (BBC)