[3] Following his time at Harvard Law, Kelly clerked for federal judge Barry Moskowitz,[3] and subsequently entered private practice with the firms Wilson Sonsini Goodrich & Rosati and Baker & McKenzie.

Kelly left the firm to become Silicon Valley's first "chief privacy officer", holding the position at Kendara, Excite@Home, and Spoke Software prior to joining Facebook in September 2005.

[4][5] Joining Facebook as the fledgling company's first attorney, Kelly would serve as Chief Privacy Officer, General Counsel, Head of Global Public Policy, and Vice President of Corporate Development.

[6] Kelly's development of the site's safety and security policies around real world identity and deployment of a highly trained staff for rule and law enforcement are credited as critical elements in the company's success.

At Facebook, Kelly worked with Attorneys General in all 50 states to develop safeguards protecting children from sexual predators and represented the company in complex situations involving privacy and intellectual property in the digital age.

[8][9] Kelly has been a producer on multiple independent films, including Olive, The Power of Two, Once Upon a Time in Queens, and the award-winning documentary, Jiro Dreams of Sushi.