Fëanor has been mentioned a few times in The Rings of Power, and Celebrimbor uses the Elf's hammer to make his rings. In Tolkien's writings, Fëanor was the forger of the Silmari

The Rings of Power is set during the Second Age of Middle-earth, thousands of years before the likes of Frodo and Bilbo and Aragorn were born. But there are still characters from the original Lord of the Rings story around during this time.