John Wemmick is a fictional character in Charles Dickens's novel Great Expectations. He is Mr Jaggers's clerk and the protagonist Pip's friend. Some scholars consider him to be the "most modern man in the book". Additionally, Wemmick is noted as one of Dickens's "most successful" split characters, insofar as Wemmick's character represents an exploration of the "relationship between public and private spheres in a divided existence".

John Wemmick is a bill collector for the lawyer Mr Jaggers. The job requires a demanding, uncaring attitude, a personality the working Wemmick takes on. To impress and stay in the favour of his boss, Mr Jaggers, he berates Jaggers's clients with disdain. He is described as having "the same air of knowing something to everybody else's disadvantage, as his master had". His professional attitude contrasts with Wemmick's more outwardly pleasant home and personal life. Jaggers was a self centered man who did not seem to pay Wemmick well, and when Pip tried to buy a boat he had made fun of him, calling the young boy poor.

More Info: en.wikipedia.org