John of Hazelgreen or Jock O'Hazeldean is Child ballad 293. The Jock O'Hazeldean variant was published by Sir Walter Scott.
A man asks a maid why she is weeping; it is for the love of John of Hazelgreen. He offers to marry her to his oldest, or youngest, son if she will forsake him, and she refuses. Nevertheless, he takes her with him, and he proves to be John of Hazelgreen's father, and informs his son that he is marrying her that day.