Based clothing such as a red and black tiger striped tank top, the 11-month-old child of Spears and Kevin Federline was given the tongue-in-cheek distinction in the September issue of Esquire, ABC News reported.
The magazine's choice, however, is being blasted by both fashion and child health experts.
Psychologist Dr. Bill Maier told ABC such a distinction will be harmful when Sean Preston reaches school age.
Peers will see such things written about him and repeat them, the doctor said.
Style writer Rachel Weingarten called the Esquire article over the line.
"... Even I think it's a little more than mean-spirited to have chosen a 1-year-old as the worst-dressed man."