Mary, Queen of Scots became queen when she was just 6 days old. She was born on December 8, 1542, and her father died on December 14, 1542, which made her Queen of Scotland.

Quick Scoop

  • She inherited the throne as an infant, not as a child or teenager.
  • Some sources round this to “about a week old,” but the exact age is 6 days.

TL;DR: Mary was only 6 days old when she became queen.