“I’m proud to be British,” she said in a statement.
She was accompanied by her parents and her husband, retired soccer star David Beckham. The couple’s four children did not attend.
The 43-year-old Beckham has made a success of her fashion line despite initial skepticism about her ability to cross over from singing to design.
Olympics star Jessica Ennis-Hill and award-winning actor Mark Rylance also received honors.