Sir Andrew Barton (c. 1466 – 2 August 1511), Scottish sailor from Leith, served as High Admiral of the Kingdom of Scotland.
Some of Andrew Barton's trading voyages to Flanders ports in the 1490s are recorded in the Ledger of Andrew Halyburton. He was the oldest of three brothers, a younger brother Robert Barton of Over Barnton became Lord High Treasurer of Scotland.
Andrew became notorious in England and Portugal as a 'pirate', though as a seaman who operated under the aegis of a letter of marque on behalf of the Scottish crown, he may be described as a privateer. The letter of marque against Portuguese shipping was originally granted to his father John Barton by James III of Scotland before 1485. John's ships had been attacked by Portuguese vessels when he was trading at Sluis in Flanders.
James IV revived the letters in July 1507. When Andrew Barton, sailing in the Lion tried to take reprisals against Portuguese ships in 1508, he was detained by Dutch authorities at Veere. James IV had to write to Maximilian, the Holy Roman Emperor, and others to get him released in 1509. Andrew then took a Portuguese ship which carried an English cargo, leading to more difficulties, and James IV had to suspend the letter of marque for a year. Andrew captured a ship of Antwerp in 1509, the Fasterinsevin (the Shrove Tuesday), which did not come within his letter of marque. James IV ordered him to recompense the captain Peter Lempson and his officers for her cargo of woad and canvas.
The Bartons were in demand to support John, King of Denmark, and were allowed by him to harass the shipping of Lübeck. In return for this service, John of Denmark sent James IV timber for the masts of his ships from Flensburg. Andrew joined John's service briefly in the spring of 1511, but sailed away without permission, also taking a ship that James IV had given to John.