The sixth most powerful woman in the world, according to Forbes magazine last May, said Facebook users retain control of their data and personalised adverts do not compromise them.
In an interview with BBC Breakfast, she said: "Privacy is of the utmost concern and importance to Facebook and it's important to us that the people who use our service know we are very protective of them. It is their data, they have control of it, they share it.When we are able to personalise ads, we are doing that without sharing their private data with any advertisers."
Her comments follow the launch of the UK and Ireland SMB Council at the firm's international headquarters in Dublin, which aims to boost participation between Facebook and businesses.
Mrs Sandberg said working with small to medium-sized businesses was important because "the opportunity of this huge technological shift we're going through is one we can work together (on).
"We have 25 million small to medium-sized businesses around the world that use our free products to set up a page and use it to reach their customers."