John Thorpe is a character in Northanger Abbey. He is a son of Mrs. Thorpe and the late Mr. Thorpe. He is brother to Isabella Thorpe and a few other Miss Thorpes. He is friends with James Morland, Catherine Morland's brother.
John Thorpe went to the same school as James Morland, and the other young man spent Christmas with the Thorpes one year. The Thorpe family all believed him to be wealthier than he was, although not by his own admission. This prompted Isabella Thorpe to pursue him quite unashamedly.
John Thorpe and James Morland ran into their sisters while in Bath. He offered to drive Catherine to her destination. It was clear that Isabella was playing matchmaker to an extent, but mostly she wanted to remain alone with James Morland, as she had designs on him. He had bought a very fashionable gig for 50 guineas, and told Catherine all about it, showing his crudeness.
He also seemed to be under the impression that Catherine was Mr. Allen's goddaughter, which would leave her the heiress of most, if not all, of his fortune. Catherine put him to rights immediately, not even pretending to a position she did not have, but he didn't seem convinced. Later, he continued to show his ill-breeding by interrupting Catherine while she was dancing with Henry Tilney, and he seemed to show a kind of bemused jealousy, as if he did not quite believe that a pretty young lady would ignore his attentions for someone else. Tilney came over later to ask about it, as he had been very put off by Thorpe's behavior. Catherine assured him that she only talked to Thorpe because he was a particular friend of her brother's, and for really no other reasons.
After Isabella and James Morland became officially engaged, John asked Catherine whether or not it would be agreeable if he visited her in Wiltshire. She, thinking he would be coming just as a friend and not as a suitor, encouraged his visit and said that company is always quite fun to have around. It is believed that either Isabella or John let this slip to the Tilneys in order to put off Henry Tilney from pursuing Catherine.
When it became known to the Thorpes that the Morlands were not as wealthy as they thought, John distanced himself from Catherine, and Isabella accused her of leading two men on—which she was not.
He swears quite a bit and is very vain about everything. He makes up stories about himself that portray him in a heroic or very positive light. His mother dotes on him, and it's clear that she is where he gets most of his vanity. He and his sister are both very ambitious people, although Isabella is more cunning than he. They make a very effective team while trying to snag the Morlands in the marriage mart, but neither of them truly research carefully, neglecting to realize that the Morlands were only moderately wealthy.