The 50cm-long, yellow strands were found in a pot that had probably been buried during a catastrophic flood.
Radiocarbon dating of the material taken from the Lajia archaeological site on the Yellow River indicates the food was about 4,000 years old.
Scientists tell the journal Nature that the noodles were made using grains from millet grass - unlike modern noodles, which are made with wheat flour.
The discovery goes a long way to settling the old argument over who first created the string-like food.
Professor Houyuan Lu said: "Prior to the discovery of noodles at Lajia, the earliest written record of noodles is traced to a book written during the East Han Dynasty sometime between AD 25 and 220, although it remained a subject of debate whether the Chinese, the Italians, or the Arabs invented it first.
"Our discovery indicates that noodles were first produced in China," the researcher from the Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, explained to BBC News.
The noodles were extremely delicate, the researchers said, and quickly turned to powder when they were exposed to the air. They were not in the least bit appetizing.
"No one has tasted them," said Houyuan Lu, a spokesman for the Chinese Academy of Sciences in Beijing. "They resemble the La-Mian noodle, a traditional Chinese noodle that is made by repeatedly pulling and stretching the dough by hand."
The noodles were made from millet, while modern Asian noodles and Italian pasta are made from durum wheat or bread wheat. Eating them would have required powerful slurping. At 50 centimetres, they are about twice as long as a piece of spaghetti, and only about 0.3 centimetres in diameter. A paper describing their discovery was published in the latest edition of the British journal Nature.
Prior to this discovery, the researchers said, the earliest written record of noodles dates back to about 1900 years ago. A book written during the East Han Dynasty (AD 25-220) contains the first description of the origin and production of noodles in China.
"Other theories suggest noodles were first made in the Middle East and introduced to Italy by the Arabs. Italians are widely credited for popularizing the food in Europe and spreading it around the world," Dr. Lu said, informs the Globe.