The South Pole Telescope (SPT) is a 10-metre (390 in) diameter telescope located at the Amundsen–Scott South Pole Station, Antarctica. The telescope is designed for observations in the microwave, millimeter-wave, and submillimeter-wave regions of the electromagnetic spectrum, with the particular design goal of measuring the faint, diffuse emission from the cosmic microwave background (CMB). The first major survey with the SPT—designed to find distant, massive, clusters of galaxies through their interaction with the CMB, with the goal of constraining the dark energy equation of state—was completed in October 2011. In early 2012, a new camera (SPTpol) was installed on the SPT with even greater sensitivity and the capability to measure the polarization of incoming light. This camera operated from 2012–2016 and was used to make unprecedentedly deep high-resolution maps of hundreds of square degrees of the Southern sky. In 2017, the third-generation camera SPT-3G was installed on the telescope, providing nearly an order-of-magnitude increase in mapping speed over SPTpol.

The Amundsen–Scott South Pole Station is a United States scientific research station at the South Pole of the Earth. It is the southernmost point under the jurisdiction of the United States. The station is located on the high plateau of Antarctica at 9,301 feet (2,835 m) above sea level. It is administered by the Office of Polar Programs of the National Science Foundation, specifically the United States Antarctic Program (USAP). It is named in honor of Norwegian Roald Amundsen and Briton Robert F. Scott, who led separate teams that raced to become the first to the pole in the early 1900s.