Ochiltree, a barony in the county of Ayr, Scotland, from which a title in the Scottish peerage was held in the 16th and 17th centuries by a branch of the house of Stewart. Sir Andrew Stewart (d. 1488), chancellor of Scotland, a great-grandson of the regent Albany (d. 1420), was created Baron Avandale or Avondale about 1457. This peerage became extinct at his death, but was revived about 1499 in favour of his nephew and heir Andrew Stewart, who, being killed at the battle of Flodden in 1513, was succeeded by his son Andrew, 2nd Baron Avandale of this creation; and the latter obtained an act of parliament in 1543 empowering him to exchange the title of Lord Avandale for that of Lord Ochiltree, or Lord Stewart of Ochiltree. His son, Andrew, 2nd Lord Ochiltree (d. c. 1600), was a zealous supporter of the lords of the congregation, and especially of John Knox, in the struggle against Mary queen of Scots, and was wounded at the battle of Langside while fighting against the queen. Of his five sons, William was slain by the earl of Bothwell in 1588, and James, created earl of Arran in 1581, was the father of Sir James Stewart of Killeith who became 4th Lord Ochiltree in 1615; his daughter Margaret was the second wife of John Knox. His brother Henry Stewart married Margaret Tudor, widow of James IV. of Scotland, and was created Baron Methven by James V. in 1528; and another brother, Sir James Stewart of Beath, was ancestor of the Stewart earls of Moray, through his son James who was created Lord Doune in 1581.
The second Lord Ochiltree was succeeded in the peerage by his grandson Andrew, who resigned the title in 1615, and having been summoned by writ to the Irish House of Lords was created Baron Castle Stewart in the Irish peerage in 1619. The barony of Ochiltree which he thus resigned was conferred in 1615 on his cousin Sir James Stewart of Killeith (see above), son of the earl of Arran; and on the death without issue of his son William, 5th Lord Ochiltree, in 1675, the title became extinct. In 1774 Andrew Thomas Stewart successfully claimed the barony of Castle Stewart in the peerage of Ireland as heir male under the creation of 1619; but although he was permitted in 1790 to vote as Lord Ochiltree in an election of Scottish representative peers, his claim to this barony as collateral heir of the grantee of 1615 was disallowed by the House of Lords in 1793.
