The company, which owns the fabled New York arena, purchased the venue, located in the Los Angeles suburb of Inglewood, a year ago for $23.5 million in a bid to return it to its former prominence and compete with the Staples Center in downtown Los Angeles.
During its 1970s and 1980s heyday, the Forum hosted NBA basketball championships and top-billed rock and pop concerts, but its star faded after the Lakers and Kings moved to the new Staples Center in 1999.
Madison Square Garden Co - which also owns Radio City Musical Hall in New York, and venues in Boston and Chicago - said the Forum would expand the company's presence to the West Coast.
"Our acquisition and revitalization of the Forum is a perfect complement to the Madison Square Garden arena," Hank Ratner, MSG president and CEO, said in a statement. "It now allows us to have world-class venues in both New York and Los Angeles, linking the two top entertainment markets in the country."
Rock group The Eagles, whose peak years in the 1970s mirrored those of the Forum, will be the refurbished arena's first event, playing three consecutive concerts in January.
The venue, which was used for a church's Sunday service, will be renamed The Forum Presented by Chase and primarily focus on music and entertainment. It will seat up to 17,500 people.
(Reporting by Eric Kelsey; Editing by Ken Wills)