Mary was the fifth child of Henry VII of England and Elizabeth of York, and the youngest to survive infancy. She was born at Richmond Palace.   She and Henry VIII were so close as children that he later named his daughter, the future Queen Mary I, after her. 

In her youth Mary was known as one of the most beautiful princesses in Europe.  Cardinal Wolsey negotiated a peace treaty with France and on October 9, 1514, at the age of 18, Mary married 52-year-old King Louis XII.  Despite two previous marriages, Louis had no living sons.  He died on January 1, 1515, less than three months after marrying Mary, (rumored to be due to being reputedly worn out by in the bedchamber). The marriage did not produce any children. 

Henry VIII wanted any future marriage to be to his advantage.  He sent Duke Charles Brandon to bring Mary back to England in late January 1515 and made the Duke promise that he would not propose to her.  However, the couple married in secret in France on March 3, 1515.  This was treason, as Brandon had married a Royal Princess without Henry's consent. The King was outraged, and the Privy Council urged that Brandon should be imprisoned or executed. Because of the intervention of Thomas Wolsey, and Henry's affection for both his sister and Brandon, the couple were let off with a heavy fine. They were officially married on May 13, 1515 at Greenwich Palace.

Even after her marriage to Duke Charles Brandon, Mary was normally referred to at the English Court as "the French Queen", and was not known as "the Duchess of Suffolk" in her lifetime. Mary spent most of her time at the Duke's country seat of Westhorpe Hall in Suffolk.

She died at Westhorpe, Suffolk, on June 1533.  She was first interred at Bury St Edmunds Abbey but was later moved to nearby St Mary's Church, when the abbey was destroyed during the Dissolution of the Monasteries.