The Stringer Family is a family that only appeared in The Third Wheel. The family has two children, who go to Church School, a boy about Manny's age named Wesley and a girl named Laurel, who is Greg's age. They were once invited to the Heffley's for dinner and Mrs. Stringer is the friend of Greg's mom Susan. Manny is scared of Wesley because Wesley told him that he is a vampire.
- Mr. Stringer-Husband of Mrs. Stringer and the father of Laurel and Wesley.
- Mrs. Stringer-Mother of the Stringer family, Mr. Stringer's wife and the mother of Laurel and Wesley.
- Wesley Stringer-The youngest child of the Stringer family, preschooler.
- Laurel Stringer-The oldest child of the Stringer family.
- Even though they didn't appear as main characters, they still played a major role in the book.