This earldom consisted of Dunbartonshire, parts of Renfrewshire, Stirlingshire and Perthshire. The Earls of Lennox came from the ancient Celtic Mormears of Levenax.

By the end of the thirteenth centry, the Earls of Lennox were among the most powerful nobles in the area. Malcolm, the fifth Earl, led his Lennox men into England and besieged Carlisle. He is listed in the Ragman Roll that year. Because of the death of Malcolm's son, the earldom was passed through his daughter to Walter de Fasselane. In 1488, John, Lord Darnley took the title of earl of Lennox and sat in the first Parliament of James IV.

In the ninteenth century, the Lennoxes of Woodhead claimed the right to take over the title and honours of the ancient Earls of Lennox. Their claim was never established but nevertheless the were recognised as chief family of the name.