Sydney Henson is originally from Saugerties, New York. She began her ballet training at age 11 with Victoria Rinaldi in Saugerties. In 2020, Sydney moved to Hungary to train at the Hungarian Dance Academy, the country's national school. During this time, outside of the academy, she was also coached by Ildiko Pongor. In 2021, she continued her training at the Rock School for Dance Education in Philadelphia, working closely with Natalya Zeiger and Telmo Moriera.
Sydney has competed at Youth America Grand Prix in 2018, 2020, and 2022 and Valentina Kozlova's International Ballet Competition in 2017, 2018, and 2022. She was awarded 1st place in classical at the Philadelphia YAGP semi-finals in 2022 and competed in their Finals. At the 2022 VKIBC finals, Sydney was awarded 3rd place in the senior category, in turn being awarded a contract with Cleveland Ballet for their 2022-2023 season.