The origin of the name is obscure, but it is found in Renfrewshire from the 12th century and in 1246 Robert de Sempill, later a chamberlain of Renfrew, witnessed a charter to Paisley Abbey. His sons Robert and Thomas, who supported Robert the Bruce, were rewarded for their services with all the lands around Largs in Ayrshire - confiscated from the Balliols - and half the lands of Longniddry. The lands of Elliotstoun, which became the territorial designation of the chiefly line, were acquired prior to 1344.

Sir Thomas Sempill of Eliotstoun fell at the Battle of Sauchieburn in 1488 and his only son, John was created Lord Semple, probably in the same year. He founded the collegiate Church of Lochwinnoch in 1505 and rebuilt a castle at the eastern end of the loch which he named Castle Semple. His grandson, "The Great Lord Semple", supported the Queen Regent, Mary of Guise, widow of James V and was a faithful adherant of Mary Queen of Scots until the murder of Darnley. After that, he joined the supporters of the infant James VI and for his services received a charter to the lands of Paisley Abbey, forfeited from Lord Claud Hamilton who was later able to regain them.

His son, Robert, who succeeded as fourth Lord Sempill in 1572, was appointed Privy Councillor by James VI and was sent as Ambassador to Spain. A faithful Catholic, he could hold no other public office and was excommunicated by the General Assembly of the Church of Scotland in 1608 as an "obstinate papist".

The fifth and sixth Lords lived largely private lives attending to their estates which became somewhat diminished due to adherance to the royalist cause during the Civil War. The eighth Lord Sempill was the first to become a Protestant and the first to sit in Parliament since the reign of Mary Queen of Scots. He was succeeded by his elder sister, Ann in 1684 under a deed of entail and she obtained a new charter to the title in 1688. Her eldest son francis, the tenth Lord, was a staunch opponent of the Union with England and voted against every article in Parliament.

In 1835 the title once more passed to the female line, when Maria Janet Sempill succeeded her brother, the fifteenth Lord. She also died without issue, in 1884 and the title passed to her great nephew Sir William Forbes of Craigievar. The family have lived in Aberdeenshire ever since. John, the eighteenth Lord Sempill had a distinguished military career and was followed by his son Francis, the nineteenth Lord Sempill, who was an intrepid air pioneer and the first man to fly from John O'Groats to Lands' End.. He was a Represenative Peer of Scotland and attended Parliament up to his death in 1965. At this point, the two titles split with his daughter Ann becoming Baroness Sempill and his brother retaining the Forbes baronetcy, as it could not pass down through the female line. Craigievar was sold to the National Trust of Scotland and is considered one of the finest Castles in the country.

In 1995 the current Lord Sempill, 21st in line, inherited the title from his mother, who like her father had dutifully attended the House of Lords. Lord Sempill now resides in Leith, Edinburgh. He is married to Josephine and has two children. Francis, Master of Sempill and the Hon. Cosima Sempill. He currently sits in the House of Lords with special interests in matters relating to Scotland and South Africa. It is his desire to re-establish a Semple family association, thereby reuniting a family with over 500 years of history.