Stardom Cinderella Tournament 2021 ~ Day 1

Cinderella Tournament 2021 ~ Day 1 was a professional wrestling event promoted by World Wonder Ring Stardom, held on April 10, 2021 at Korakuen Hall in Tokyo, Japan. It served as the first show for the company's annual single-elimination tournament, which would become affected by illness and constant rescheduling due to the then-ongoing COVID-19 pandemic.