Ben Chestnut is an American Internet entrepreneur, best known as the co-founder and former CEO of Mailchimp, an email marketing company. He co-founded Mailchimp, also known as Rocket Science Group, with Dan Kurzius in 2001. Under his leadership, the company was bootstrapped to $1 billion in annual recurring revenue (ARR) and was acquired by Intuit in 2021 for $12 billion, reportedly the largest acquisition of a bootstrapped company in history.