This is an ancient name spelt as Leal, Leall or Leale, from the Old Scottish-Gaelic pre 15th Century “leal”, itself a form of the French “leial”, a Norman introduction. The meaning is given as “loyal” or “faithful”, but as the ultimate origin is the Latin “legalis”, the name may be a metonymic for a lawyer. The surname is particularly early for Scotland, as shown below, and further recordings include: William Leal, of Forres, Scotland (a shoemaker) in 1765, whilst in 1773, Kenneth Leal was executed and hung in chains for robbing the Edinburgh Mail! The Leals seem to have fared better in England, being granted a Coat of Arms (circa 1750) in Kent, the shield being a red field, crossed by a gold bend between six crescents, signifying defeat of the Turks. The name recordings include: Ramsee Leyle, of Kensington, in 1609; George Leil, of Westminster, in 1642; and George Leal, a christening witness at St. Mary Le Bone, London, on May 2nd 1806. The first recorded spelling of the family name is shown to be that of Andrew Leal, which was dated 1479, treasurer of the Church of Aberdeen, Scotland, during the reign of King James 1V of Scotland, 1488 – 1533. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to “develop” often leading to astonishing variants of the original spelling.
Source: Surname Database