The former Leeds and Everton forward has signed a two-year contract as Wanderers boss Dougie Freedman continues to reshape his squad for the new season.
Freedman knows the 29-year-old well from his own stint at Elland Road, and the Scotsman revealed he has been hoping to secure Beckford's services for some time.
"We have worked very hard in order to bring Jermaine to the club," Freedman said.
"Jermaine is someone I know, and I have previously played alongside him, so I know his character.
"He is a goal scorer."