<page_title> The Simpsons (season 21) </page_title> <section_title> Episodes </section_title> <table> <cell> "Once Upon a Time in Springfield" <col_header> Title </col_header> <row_header> 451 </row_header> </cell> <cell> 14.62 <col_header> U.S. viewers (millions) </col_header> <row_header> 451 </row_header> </cell> </table>
The most viewed episode of The Simpsons season was "Once Upon a Time in Springfield", watched by 14.62 million.