Spader joined the cast in Season 8, after the workplace comedy's original star Steve Carell left to focus on his film career.
"James always wanted this to be a one-year arc, and he now leaves us having created one of the most enigmatic and dynamic characters in television," executive producer Paul Lieberstein told Variety. "He's been a great friend to me and the show, helping us successfully transition into the post-Michael Scott years, and I'm grateful for that."
The entertainment industry trade newspaper said it is unclear how Spader's character, company Chief Executive Officer Robert California, will be written out of the series.
Spader is an Emmy Award-winning actor, who previously starred on "The Practice" and "Boston Legal."