Feldhofer 1 or Neanderthal 1 is the scientific name of the 40,000-year-old type specimen fossil of the species Homo neanderthalensis. The fossil was discovered in August 1856 in the Kleine Feldhofer Grotte cave in the Neander Valley (Neandertal), located 13 km (8.1 mi) east of Düsseldorf, Germany.

In 1864, the fossil's description was first published in a scientific journal, where it was officially named. Neanderthal 1 was not the first Neanderthal fossil ever discovered. Other Neanderthal fossils had been found earlier but were not recognized as belonging to a distinct species.

Limestone has been mined in the Neander Valley since the early 16th century. By the mid-19th century, mining operations had expanded to an industrial scale. In August 1856, two Italian workers extended the entrance to the Kleine Feldhofer Grotte by removing the naturally sintered, rock-hard clay layers embedded in the limestone of the cave. During the removal of the sediment fillings, the workers unearthed fossilized bones at a depth of 60 cm (24 in). Initially unnoticed, the bones were discarded among the mud and debris and scattered throughout the valley.

The discovery came to the attention of the cave's owner, Wilhelm Beckershoff, who assumed the bones belonged to a cave bear. Beckershoff, along with quarry co-owner Friedrich Wilhelm Pieper, retrieved 16 bones and fragments from the rubble and handed them to Elberfeld teacher and fossil collector Johann Carl Fuhlrott. Among the preserved remains were a skullcap with a fragment of the left temporal bone, a fragment of the right scapula, a right clavicle, both humeri (with the right side intact), a complete right radius, fragments of the right and left forearm bones, five ribs, an almost complete left half of the pelvis, and both femora.

Fuhlrott reportedly recognized immediately that the remains belonged to a human who significantly differed from modern humans. Without his consent, a notice was published on September 4, 1856, in the Elberfeld newspaper and the Barmer Local Journal:

In neighboring Neanderthal, a surprising discovery was made in recent days. The removal of the limestone rocks, which certainly is a dreadful deed from a picturesque point of view, revealed a cave that had been filled with mud-clay over the centuries. While clearing away this clay, a human skeleton was found. Undoubtedly, it would have been ignored and lost if not for the timely intervention of Dr. Fuhlrott of Elberfeld, who secured and examined the find. Examination of the skeleton, particularly the skull, suggests it belonged to the tribe of the Flat Heads, which still exists in the American West and of which several skulls have been found in recent years on the upper Danube in Sigmaringen. Perhaps this find can help determine whether the skeleton belonged to an early central European native or simply to one of Attila's roaming horde.

This report drew the attention of two Bonn professors of anatomy, Hermann Schaaffhausen and August Franz Josef Karl Mayer. They contacted Fuhlrott and requested to examine the bones. Fuhlrott personally brought the remains to Bonn during the winter, where Schaaffhausen conducted an investigation. On June 2, 1857, Schaaffhausen and Fuhlrott presented their findings to the members of the Natural History Society of the Prussian Rhineland and Westphalia. Paleoanthropologist Ian Tattersall summarized their findings:

Here, Fuhlrott summarized the history of the discovery, based on a careful survey of the workers who had excavated the finds. He emphasized the age of the bones, evident from the thickness of the overlying strata [...] as well as from the strong mineralization and dendrite formation on the surface, also present in the bones of extinct giant cave bears. Schaaffhausen described and interpreted the find.