Mary I may refer to:
- Mary I of England — Queen of England; daughter of Henry VIII (1516–1558)
- Mary I of Scotland — Queen of Scotland; famously known as Mary, Queen of Scots (1542–1587)
This is a disambiguation page; that is, one that points to other pages that might otherwise have the same name. If you followed a link here, you might want to go back and fix that link to point to the appropriate specific page.