World 1-S

World 1-S or World 1-Secret may refer to:
 * Exercise in the Skies, World 1-S in Yoshi's Island: Super Mario Advance 3.
 * Welcome to Yoshi Tower!, World 1-S in Yoshi's Island DS.
 * Diagonal Valley Rally, World 1-S in Yoshi's New Island.
 * Hang Tongue!, World 1-S in Yoshi's Woolly World.
 * The Hidden Bridge, World 1-S in Mario + Rabbids Kingdom Battle.