Gerard Legh or Leigh (died 1563) was an English lawyer, known as a writer on heraldry.
He was the son of Henry Legh, draper, of Fleet Street, London, by his first wife Isabel Cailis or Callis.
Richard Argall of the Inner Temple supplied a prefatory address and probably part of the latter passages of the book.
In endeavouring to explain the art of heraldry, Legh is purposely obscure from fear of trenching on the official privileges of the College of Arms.
Its theories on gentility are based on those of the Boke of St Albans, with minor modifications; the consequence being that "highly restrictive definitions of gentility and right to bear arms without foundation in common law or long established usage were widely circulated.