Beckham, 37, left the Los Angeles Galaxy in December after the team won its second Major League Soccer trophy, the BBC reported.
He is expected to begin training with PSG within two weeks. He had been training with Arsenal.
At Paris St. Germain, he will be joining a squad that already includes Zlatan Ibrahimovic, Thiago Silva, Lucas Moura and Ezequiel Lavezzi.
Beckham reportedly had offers from 12 different teams before deciding to go with PSG.
He recently announced he was permanently moving his family to London, but said his decision on what club to play with would be based on "footballing reasons."