William Henry Green II is born in Indianapolis, Indiana, to Sydney and Mike Green. He is the younger brother of John Green.

Growing up in Orlando, Florida, Hank develops an interest in science, technology, and creative writing, traits later showcased in his online content. He shows a keen aptitude for learning and a strong desire to understand the world around him.

Hank graduates from Eckerd College in St. Petersburg, Florida, with a Bachelor of Science degree in Biochemistry. This education provides him with a strong scientific foundation that he will later utilize in his science communication work.