Steinberg, who is also a CNBC on-air and online contributor, will join Lerer Ventures as a partner and remain an advisor to the company. However, his next career move is still undecided.
"I have a desire to build and create something different and new," Steinberg told CNBC. "I haven't settled on what it is yet."
He added that now is a good time for him to leave because the company is thriving.
"I think if you love and you care about a company, you want to leave when things are good," Steinberg said. "You don't want to leave when things are in bad shape."
Steinberg joined BuzzFeed in 2010 and has seen the company grow from 15 to 500 employees. He's played a primary role in developing the company's successful native advertising strategy.
"When I got there there were questions about whether native content advertising could be business. And for the most part, with a small team, we put together the first pitches and talked to brands and agencies. We built the defining ad model for social and we've built a whole new kind of advertising," Steinberg said.
Steinberg said BuzzFeed execs have not yet decided if they will restructure responsibilities or hire someone to take on Steinberg's role.
The news was first reported by Business Insider.