John Erskine, 5th Lord Erskine (died 1555) was a Scottish nobleman. His family was claimant to the earldom of Mar; when this was recognized in 1565 John was acknowledged, retrospectively, as the 17th Earl. On 3 August 1522, Erskine was appointed keeper of the ten-year-old King James V of Scotland and Stirling Castle. He had strict instructions from Margaret Tudor to hold the castle keys and set a password every night for the King's guards. The instructions were given again by act of the Parliament of Scotland in 1523.
In 1535 he travelled to England to collect the collar of Order of the Garter from Henry VIII of England on behalf of James V. The ceremony took place at Windsor Castle and later Erskine met Henry VIII at Thornbury Castle. James V had given Lord Erskine a detailed instruction about his precedence in the Garter Chapel;
"Ye shall purchase to have the place was promised to us next to the King of France amongst kings, and failing thereof that ye take documents to fulfill for our part and leave it so."
Erskine returned to London where Cromwell's servant John Gostwyk gave him a gift of silver plate, £20 to his companion the Lyon King of Arms, David Lyndsay, and 80 crowns to the Rothesay Herald.
John Erskine was also a commissioner for the marriage negotiations of James V and Mary of Bourbon. After James married Madeleine of Valois, Mar took receipt of Dunbar Castle, which was formerly garrisoned by John Stewart, Duke of Albany for France.