The 86-year-old sovereign swept into Prime Minister David Cameron's official residence at 10 Downing Street in central London for the gathering of senior government ministers.
The queen was to receive a diamond jubilee gift from the cabinet to mark her 60 years on the throne, and also sat in on their meeting as an observer, Buckingham Palace said.
Historically, monarchs used to chair cabinet meetings but the last one to exercise their right to attend was queen Victoria, Queen Elizabeth's great-great grandmother, who died in 1901.
Cabinet meetings usually last around an hour and a half but the queen attended for 30 minutes, before leaving with Foreign Secretary William Hague for a visit to the Foreign Office, which is on the other side of Downing Street.
The queen sat in the middle of the table, with Cameron to her right and Hague to her left.
