Charles Stuart, 1st Earl of Lennox

Charles Stuart with his elder ill fated brother Henry, Lord Darnley.

Charles Stuart, 5th Earl of Lennox (1555–1576) was the second son of Matthew Stewart, 4th Earl of Lennox and of Margaret Douglas, daughter of Margaret Tudor.

At the time of his father's death in 1571, the earl was acting as regent for the boy king James VI of Scotland and the earldom passed to the Crown. King James's father had been Henry Stuart, Lord Darnley, Charles's elder brother, who was already dead. However, shortly afterwards the title of Earl of Lennox was bestowed on Charles. He proceeded to incur the displeasure of Queen Elizabeth I of England by a hasty marriage to Elizabeth Cavendish, daughter of Bess of Hardwick, apparently at his mother's instigation. The couple had one child, Arbella Stuart, but she was prevented by the Scots from taking up the earldom because of her gender and the fact that she had been born in England. Arbella Stuart married William Seymour, 2nd Duke of Somerset.