Moskovitz was born in Gainesville, Florida and grew up in Ocala, Florida. He is eight days younger than Zuckerberg. Moskovitz is Jewish. His father was a psychiatrist and mother a teacher and an artist. He attended Vanguard High School, graduating from the IB Diploma Program. Moskovitz attended Harvard University as an economics major for two years before he moved with Mark Zuckerberg to Palo Alto. He went to work full-time on Facebook.
Four people, three of whom were roommates—Mark Zuckerberg, Eduardo Saverin, Chris Hughes, and Dustin Moskovitz—founded Facebook in their Harvard University dorm room in February 2004. Originally called thefacebook.com, it was intended as an exclusive online directory of all Harvard's students to help residential students identify members of other residences. In June 2004, Zuckerberg, Hughes and Moskovitz took a year off from Harvard and moved Facebook's base of operations to Palo Alto, California, and hired eight employees. They were later joined by Sean Parker. At Facebook, Moskovitz was the company's first chief technology officer and then vice president of engineering; he led the technical staff and oversaw the major architecture of the site, as well as being responsible for the company’s mobile strategy and development.
On October 3, 2008, Moskovitz announced that he was leaving Facebook to form a new company called Asana with Justin Rosenstein, an engineering manager at Facebook. Moskovitz was also the biggest angel investor in the mobile photo-sharing site Path, run by another former member of Facebook, David Morin. It was reported that Moskovitz's advice was important in persuading Morin to reject a $100 million offer for the company from Google, made in February 2011.
Moskovitz co-founded the philanthropic organization Good Ventures with his girlfriend (and now wife) Cari Tuna in 2011. In June 2012, Good Ventures announced a close partnership with charity evaluator GiveWell. Both organizations "are aiming to do as much good as possible" and thereby align with the goals of effective altruism. Good Ventures has donated approximately $100 million from 2011 onward to GiveWell top charities Against Malaria Foundation, GiveDirectly, Schistosomiasis Control Initiative, and Deworm the World Initiative, as well as standout charities (see Good Ventures for more) and other effective altruist organizations.
The joint collaboration with GiveWell led to a spinoff called the Open Philanthropy Project, whose goal is to figure out the best possible way to use large sums of money (starting with Moskovitz's multi-billion-dollar fortune) to do the most good. As of 2016, the Open Philanthropy Project is in the process of becoming a separate organization, but it has already made over $40 million in grants (see Open Philanthropy Project#Grants made for more).
Moskovitz and Tuna are also the youngest couple to sign Bill Gates and Warren Buffett’s Giving Pledge, which commits billionaires to giving away most of their wealth in the form of philanthropy.
Moskovitz has voted for the Democratic Party candidates in all elections where he has voted, but he has written: "Though we’ve voted for the Democratic nominee each of the times we’ve cast a ballot, we’ve considered ourselves independent thinkers who respect candidates and positions from both sides of the aisle." Prior to their donation for the 2016 election cycle, Moskovitz and Tuna had donated roughly $10,000 over their lifetime to federal candidates, most of it to Sean Eldridge, the husband of Facebook co-founder Chris Hughes.
For the 2016 United States Presidential election, Moskovitz announced that he and his wife are donating $20 million to support Hillary Clinton, the Democratic Party nominee, arguing that the dangers of a Trump presidency are significant, and that they are making their donation despite being skeptical of allowing large donors to influence election cycles through money. The New York Times quoted Moskovitz's blog post on the subject: "The Republican Party, and Donald Trump in particular, is running on a zero-sum vision, stressing a false contest between their constituency and the rest of the world." This makes him the 3rd largest donor in the 2016 campaigns.
Moskovitz is married to Cari Tuna. Tuna currently works full time on Good Ventures, the couple's private foundation, as well as the Open Philanthropy Project, a spinoff of a collaboration between Good Ventures and GiveWell. Tuna is a former Yale Daily News writer and Wall Street Journal journalist.
Moskovitz and Tuna attend Burning Man regularly, and Moskovitz has written about his reasons for doing so. Moskovitz's attendance at Burning Man has been the subject of some press coverage.
Moskovitz is played in the film The Social Network by actor Joseph Mazzello. Responding to a question on Quora, Moskovitz said that the film "emphasizes things that didn't matter (like the Winklevoss brothers, whom I've still never even met and had no part in the work we did to create the site over the past 6 years) and leaves out things that we really did (like the many other people in our lives at the time, who supported us in innumerable ways)."