Adam D'Angelo (born August 14, 1984) is an American internet entrepreneur. He is best known for his role as the co-founder and CEO of Quora, based in Mountain View, California, and as the first Chief Technology Officer of Facebook (now Meta).

Adam D'Angelo was born on August 14, 1984, in Redding, Connecticut, United States. He attended Phillips Exeter Academy for high school. While a student there, he developed the Synapse Media Player (a music suggestion program) with Exeter classmate Mark Zuckerberg and others.

From 2002 to 2006, D'Angelo attended the California Institute of Technology, where he graduated with a B.S. in Computer Science.

In 2004, while attending college, D'Angelo created the website BuddyZoo, which allowed users to upload their AIM buddy list in order to compare with those of other users. BuddyZoo also generated network graphs based on these lists.

D'Angelo joined Facebook shortly after its launch in 2004, and served as its chief technology officer (CTO) from 2006 to 2008, and as its vice president of engineering until 2008.

In June 2009, D'Angelo co-founded Quora with former Facebook software engineer, Charlie Cheever. In May 2012, he invested $20 million of his own money in Quora as part of the company's $50 million Series B round of financing.

D'Angelo was also an early investor in Instagram before its 2012 acquisition by Facebook, Asana, a work management platform, and Lunchclub, a networking platform using artificial intelligence.

D'Angelo is the founder of an AI startup, Poe. Poe is currently integrated within Quora as well.