J. William McAllister is considered the wealthiest man in town, possibly over the Newmans, the Wallingfords, the Albrights and the Darlings, with a home close to that of Mrs. Pennington Van Rensselaer. He's assisted by his doctor and wife suspiciously trying to convince him he's sick, but when the Rascals arrive delivering the laundry, Jackie removes McAllister's dark glasses, cotton ear plugs, and head bandage, helping McAllister realize he isn't sick. The gang takes him on a ride down to Emerald Beach. When their vehicle is stopped, McAllister shows a business card with just his name on it, and the the police officer is so impressed that he allows the gang to proceed as long as McAlllister drives. After the car almost totally falls apart upon reaching the amusement park, he enjoys many of the attractions with the gang, culminating in three roller coaster rides, much to the dismay of his wife and doctors.
Mr. McAllister was played by actor Henry Rattenberry.