In a soul-searching keynote speech at ad-tech conference DMEXCO, Sandberg said the company will step up to help make the world a better place.
"We get together at a challenging time for the world. People are afraid for their personal security, especially in light of recent events," Sandberg said. "People are looking for brands and companies that stand for something."
Her comments come at a time when the company is under intense media scrutiny over brand safety and providing a platform for extremist views.
She said Facebook has taken stock now its user base has reached two billion people and is considering its "mission and the place we play in the world".
"We have a very simple mission: making the world more connected and giving them the power to share," Sandberg said. "There are billions of people who are yet to be connected, so many more connections to be made. It is not enough to just connect people; we need to make sure we are bringing people together to do good."
Sandberg admits the size of its user base means it has a "real responsibility in everything we do".
She says the company is investing money and working hard to develop new tools for advertisers because it has heard their "concerns about safe environments and measurement".
"The businesses that are thriving are focusing on a mission, building a community and communicating who they are. There are risks to connecting, but the greater risk is missing out," Sandberg concluded. "We fulfil our mission at Facebook by building community and bringing the world close together by helping you fulfil your missions."