The Sino-Swedish Expedition was a bilateral Chinese-Swedish expedition, led by Sven Hedin, which carried out scientific research in north and northwest China, 1927–1935.

The Expedition looked in particular at the meteorology, topography and prehistory in Mongolia, the Gobi Desert and Xinjiang. Chiang Kai-shek was a patron of the Expedition.

Between 1927 and 1935, Hedin led an international Sino-Swedish Expedition which investigated the meteorological, topographic and prehistoric situation in Mongolia, the Gobi Desert and Xinjiang.

Hedin described it as a peripatetic university in which the participating scientists worked almost independently, while he—like a local manager—negotiated with local authorities, made decisions, organized whatever was necessary, raised funds and recorded the route followed. He gave archaeologists, astronomers, botanists, geographers, geologists, meteorologists and zoologists from Sweden, Germany and China an opportunity to participate in the expedition and carry out research in their areas of specialty.

Hedin met Chiang Kai-shek in Nanjing, who thereupon became a patron of the expedition. The Sino-Swedish Expedition was honored with a Chinese postage stamp series which had a print run of 25,000. The four stamps show camels at a camp with the expedition flag and bear the Chinese text "Postal Service of the Prosperous Middle Kingdom" and in Latin underneath, "Scientific Expedition to the Northwestern Province of China 1927–1933". A painting in the Beijing Palace Museum entitled Nomads in the Desert served as model for the series. Of the 25,000 sets, 4,000 were sold across the counter and 21,500 came into the possession of the expedition. Hedin used them to finance the expedition, selling them for a price of five dollars per set. The stamps were unpopular at the time due to the high price Hedin was selling them at, but years later became valuable treasures among collectors.

The first part of the expedition, from 1927 to 1932, led from Beijing via Baotou to Mongolia, over the Gobi Desert, through Xinjiang to Ürümqi, and into the northern and eastern parts of the Tarim Basin. The expedition had a wealth of scientific results which are being published up to the present time. For example, the discovery of specific deposits of iron, manganese, oil, coal and gold reserves was of great economic relevance for China. In recognition of his achievements, the Berlin Geographical Society presented him with the Ferdinand von Richthofen Medal in 1933; the same honor was also awarded to Erich von Drygalski for his Gauss Expedition to the Antarctic; and to Alfred Philippson for his research on the Aegean Region.

In 1930, the expedition excavated ten sites in the Juyan Lake Basin and unearthed a total of 10,200 wooden slips dating to the Western Han, which came to be known as the "old Juyan texts" in contrast to the "new Juyan texts" excavated from 1972 to 1972. In 1937, after the Second Sino-Japanese War began, Chung-Chang Shen transported these wooden slips from Beijing to the University of Hong Kong.

From the end of 1933 to 1934, Hedin led—on behalf of the Kuomintang government under Chiang Kai-shek in Nanjing—a Chinese expedition to investigate irrigation measures and draw up plans and maps for the construction of two roads suitable for automobiles along the Silk Road from Beijing to Xinjiang. Following his plans, major irrigation facilities were constructed, settlements erected, and roads built on the Silk Road from Beijing to Kashgar, which made it possible to completely bypass the rough terrain of Tarim Basin.