A villain published by DC Comics. Sinestro first appeared in Green Lantern #7 in 1961.

Sinestro is a native of the planet Korugar, whose inhabitants are a red-skinned, black haired race of humanoids. Thousands of years ago, the Guardians of the Universe, the creators of the Green Lantern Corps, had a fling with the women of Korugar. The males of the planet got annoyed that they were getting passed over by their own women for a group of short, bald, blue men in dresses. A battle ensued between the two groups with the Guardians defeating them handily. However, the Guardians decided to break off relations with the women of Korugar and to insure that they would never harm a Korugar male, they created a flaw in their Central Power Battery that if its power was used to kill a Korugar male, it would self-destruct.

Years later, Sinestro was trained and made a member of the Green Lantern Corps. He started out to be a very good Green Lantern, but eventually his desire for order and the power he wielded went to his head and he created a police state on his homeworld, making himself absolute ruler. During this time, he was ordered by the Green Lantern Corps to train a new young recruit, Hal Jordan of Earth.

Sinestro trained Jordan for a time, but eventually the two were caught up in an uprising on Korugar as the natives sought to overthrow Sinestro. The two were taken into custody by robotic enforcers the Fists of the Guardians. Sinestro was tried for his crimes and stripped of his power ring, which was given to one of the rebels from Korugar, Katma Tui. Sinestro was then banished to the antimatter universe and the planet Qward.

On Qward, Sinestro met the Weaponers of Qward, a race of beings who created advanced weaponry. They constructed for Sinestro a ring similar to the ones used by the Green Lanterns but that used yellow energy instead of green. In this way, Sinestro could take advantage of the Green Lantern's ring's weakness. Sinestro returned to the positive matter universe and clashed with the Green Lantern Corps and specifically, Hal Jordan, for many years.

After the Crisis on Infinite Earths, the Guardians of the Universe left Oa and the Green Lantern Corps was left to fend for itself. During this time, Sinestro was responsible for the destruction of the home world of one of the Green Lanterns, Kilowog. Sinestro was captured and put on trial for his crimes and found guilty by the Corps, who then decided to kill him. In doing so, the Corps caused the destruction of the Central Power Battery which had been created with the fail safe to protect Korugar males. A few rings still worked after this, due to the efforts of Hal Jordan and the spirit of Sinestro took up residence in the Power Battery.

A few years later, after the destruction of Coast City unhinged Hal Jordan, he sought to use the power of the Green Lantern Corps to undo the city's destruction. Hal Jordan made short work of many in the Green Lantern Corps as he traveled to Oa to drain the Power Battery. The Guardians attempted to stop him, by resurrecting Sinestro and pitting him against their rogue Lantern. Jordan defeated Sinestro, snapping his neck and putting a final end to the villain.