Louis the Yard Teacher is the Wayside School playground supervisor. He takes his name from the author, Louis Sachar, who once served as a schoolyard supervisor at Hillside School in Berkeley, California during his own college years. “Louis the yard teacher” is what the Hillside children called Sachar. In Wayside School Is Falling Down, the fictionalized Louis also takes care of various small tasks around the school, such as delivering packages and cleaning up the schoolyard, and he serves as a trusted confidant to many of the children. Louis’s willingness to help and his unfailing kindness demonstrate how invested he is in Wayside School and how much he loves the students. These character traits are underscored by the collection’s ending, in which Louis is the only person who remains behind at Wayside School, working night and day to remove the cows so that the school can reopen.

Louis is one of the least eccentric characters portrayed in Wayside School Is Falling Down. His behavior is generally logical and predictable; for example, he does not believe Joy’s story that she lost a bag of money in “Lost and Found,” and he takes the sensible action of reporting the discovery. Louis provides a dependable and steady adult presence at Wayside that contrasts with the unpredictable and illogical behavior of the other adults.