Michael Seibel (born October 7, 1982) is a partner at Y Combinator and co-founder of two startups – Justin.tv/Twitch and Socialcam.

[6] At Yale, he majored in political science and became friends with Justin Kan. After his graduation in 2005, he worked as a finance director for Kweisi Mfume's unsuccessful run for the U.S. Senate in 2006.

He then became CEO of Socialcam,[7] a social video-sharing app that launched in March 2011 and sold to Autodesk for $60 million in 2012 (after existing for only 18 months).

[9] In 2008, Michael Seibel was a key mentor to the co-founders of Airbnb and recommended them to Y Combinator.

[15] Some of Seibel's personal startup investments include Cruise, Brex, Figma, Rippling, Reddit, Clipboard Health, and Promise.