Hyperion, Tallest known living tree in Redwood National and State Parks, California, United States

Hyperion is a coast redwood (Sequoia sempervirens) in a remote part of Redwood National Park, California, measured at 116.07 metres in 2019. Its straight, slender reddish-brown trunk is bare over the lower two-thirds, with thin sparse branches, and carries a narrow, irregular crown of layered, drooping green foliage.

Hyperion was found on August 25, 2006, by naturalists Chris Atkins and Michael Taylor in a remote part of Redwood National Park. Stephen Sillett verified its height that year using a laser range finder and a fiberglass tape. In July 2022 the park superintendent closed the area around the tree after visitor trampling destroyed the surrounding ferns.

The tree is named after Hyperion, a Titan of Greek mythology, son of Uranus (sky) and Gaia (Earth). The name was chosen for its resemblance to the Titan, and the tree was seeded while the Chilula, a Pacific Coast Athabaskan people, inhabited the region. It appeared in the BBC Radio 4 documentary James and the Giant Redwoods by James Aldred in February 2012.

The area around Hyperion was closed by the Redwood National Park superintendent in July 2022 after visitor trampling destroyed the ferns at its base. Entering the closed zone can bring up to six months in jail and a $5,000 fine. The tallest trees open to the public, such as Helios and Icarus, stand elsewhere in the park.

Hyperion holds about 530 cubic metres of wood, a figure estimated from its trunk and crown. Its record is one of height, not mass: the tree is not the largest by volume. Woodpecker damage near the top is thought to have limited further upward growth.