Answer
MacKenzie's maiden name was Tuttle. It was her family name before she married Jeff Bezos, the e-commerce magnate and founder of Amazon, in 1993. After their marriage, she adopted the surname Bezos and was widely known as MacKenzie Bezos or MacKenzie S. Bezos until their divorce in 2019. Following the divorce, she reverted to her birth name, MacKenzie S. Tuttle.