This move marks an end to Harpo's 26-year run in the Windy City, said the Hollywood Reporter.
OWN -- The Oprah Winfrey Network - has just moved into its new space at West Hollywood's The Lot.
"I've spent more hours in this building than I have any other building on Earth.... We were here when there was nothing but hoes and rats on the street, and now it's one of the hottest neighbourhoods [in Chicago]," she said.
Winfrey noted that the top OWN execs had been going back and forth between Chicago and Los Angeles and that she wanted all her operations in one place.
OWN has been around for the past four years and plans to expand further.
Around 200 employees will be impacted by the closing of the Chicago offices.