"James will reprise his role as Robert California, this uber-salesman that has a power to convince and manipulate, like a high-class weirdo Jedi warrior," Paul Lieberstein, who is executive producer and plays HR rep Toby, said in a statement.
"He'll have been hired over the summer as the new manager, but within hours, got himself promoted. Within days, he took over the company. James has an energy that is completely his own, and 'The Office' has no tools for dealing with this guy. We're thrilled he's joining our cast."
His character first appeared in the Season 7 finale, interviewing for Michael Scott's vacant position.
Spader's character replaces Kathy Bates as CEO. She's departing the series to focus on her NBC legal drama 'Harry's Law.'
Tell us: Are you looking forward to more James Spader on 'The Office'?