Cecelia Newberry is a substitute teacher at the Bluffington School. She substituted for the vacationing Mrs. Wingo, who at that time was tending to her family. When she first came in, all the boy students fell in love, including Roger. During her week on the job Ms. Newberry had to deal with Doug's alleged bad behavior; but she knows that deep down inside that Doug really is a good kid.
Her debut and only appearance in the series is in the episode Doug's New Teacher.