More change is expected in the coming days as President Barack Obama reshapes his leadership team to gear up for a re-election bid and a more powerful Republican Party.
Gibbs said he would be leaving the White House by early February. The top contenders to replace him are two of his deputies, Bill Burton and Josh Earnest, and Jay Carney, who is communications director to Vice President Joe Biden.
By resigning his post, Gibbs is able to escape the grinding pace of the press secretary's job, make money giving speeches and spend more time with his family.
As an outside political adviser, he will still be a key voice in Obama's decision-making, and he will end up back in a pivotal role in Obama's campaign for a second term.
"What I'm going to do next is step back a little bit, recharge some," Gibbs said.
In a statement, Obama described Gibbs as a friend and one of his closest advisers.
"I think it's natural for him to want to step back, reflect and retool," the president said. "That brings up some challenges and opportunities for the White House - but it doesn't change the important role that Robert will continue to play on our team."
Gibbs expressed much gratitude for getting to serve in the White House.
"Over the course of the next two years, we're going to be involved in discussions about which direction to take this country, and in 2012, we'll have a presidential election," he said. "I don't have any fears that there won't be plenty of roles (for himself) outside of the White House."
According to Gibbs, Obama will likely announce his new chief economic adviser on Friday. And the president is also expected to have a new senior political counselor, and two new deputy chiefs of staff.
The Associated Press contributed to this report.