On April 30, 2019, Carolina traded Fox's NHL rights to the New York Rangers in exchange for a second-round pick in the 2019 NHL Entry Draft and what would become a second-round pick in the 2020 NHL Entry Draft. On May 2, Fox signed an entry-level contract with the Rangers, with a maximum entry-level salary ($925,000 plus bonuses). He won the Lars-Erik Sjoberg Award as the top Ranger rookie in training camp in 2019, and made the Rangers' Opening Night roster.