Sauron is the creator of the One Ring in J.R.R. Tolkien’s Middle-earth.
Sauron forged the One Ring in the fires of Mount Doom during the Second Age. He designed it to control the other Rings of Power and to strengthen his authority over their bearers. Because he placed much of his power into the Ring, its destruction is essential to defeating him.
The Ring is eventually carried by Frodo Baggins toward Mount Doom. Gollum takes it from Frodo at the Crack of Doom and falls into the fire, destroying the Ring and causing Sauron’s power to collapse.
Morgoth was an earlier and greater evil whom Sauron served, while Saruman became a later ally of Sauron. Celebrimbor helped create several of the other Rings but did not create the One Ring. These distinctions are important because Tolkien’s legendarium contains several ring-makers and major villains.