She married Prince William and she's the future Queen of England, but is Kate Middleton a princess? It's a question that's been asked repeatedly since the 30-year-old married into the royal family in April 2011. While the one-time commoner has often been referred to as 'Princess' Kate or 'Princess' Catherine she is technically not a princess.
Just hours before Kate Middleton and Prince William exchanged vows at their Royal wedding, Queen Elizabeth granted Prince William the titles of Duke of Cambridge, Earl of Strathearn, and Baron Carrickfergus. By marrying William, his new bride went from Kate Middleton to officially: Her Royal Highness Princess William Arthur Phillip Louis, Duchess of Cambridge, Countess of Strathearn, Baroness Carrickfergus. Kate's title and style is quite the tongue twister which is why she's often referred to as simply the Duchess of Cambridge, Princess Kate, or mostly commonly Kate Middleton.
Prince William was reportedly upset he was given a dukedom. Instead, it was suggested he wanted to remain known as Prince William and his bride Princess Catherine. But according to reports this created a predicament for the Queen as 'Princess' is typically reserved as a title given through birth not marriage.
William's mother, Princess Diana as she was commonly referred to, was actually Diana, Princess of Wales and was not actually a princess either. She was given the title of Princess of Wales when she married Charles because he was (and still is) the heir to the throne. That title is typically given to next in line to the British monarch.