The resignation is effective immediately. A CNN spokeswoman confirmed that Lewandowski is no longer serving as a contributor to the network.
Lewandowski has stayed in close touch with Trump and some top Trump aides since being fired from the campaign in June. This week there has been media discussion about Lewandowski possibly taking a role in the Trump administration.
Lewandowski did not immediately respond to a request for comment.
Earlier on Friday, Lewandowski was seen arriving at Trump Tower, where the president-elect is holding transition meetings.