The couple married in a surprise ceremony in The Hamptons on Saturday and Bridget shared the happy news on Instagram.
A source said of the ceremony: "The couple were surrounded by friends and family."
Bridget and Andrew - who has three sons - have kept their relationship largely under wraps with a source telling PEOPLE: "The groom is from New York and is Co-President of Stuart Frankel and Co., a Wall Street institutional brokerage firm. They met each other through a friend and she has been on cloud nine ever since."
Bridget has a son Jack, eight, with former boyfriend Tom Brady who she dated from 2004 to 2006.
The insider explained: "Bridget's son Jack [with ex Tom Brady] is excited to be gaining three incredible older brothers."
Bridget has starred in crime drama 'Blue Bloods', currently on its sixth season, since 2010.