Samuel Oschin telescope, Schmidt camera telescope at Palomar Observatory, San Diego County, United States.

The Samuel Oschin telescope is a Schmidt camera on Palomar Mountain in San Diego County, California, fitted with a large mirror and a wide corrector lens that together capture broad fields of the sky in a single exposure. It sits within the Palomar Observatory complex, which houses several other telescopes and is operated by Caltech.

Construction began in 1939 and the instrument entered service in 1948, initially known simply as the 48-inch Schmidt telescope. In 1986 it was renamed to honor Samuel Oschin, a philanthropist who supported the observatory financially.

The telescope's name honours Samuel Oschin, a Los Angeles businessman and philanthropist (1914–2003) whose donation to Palomar Observatory led to the renaming in 1986; before that it was simply the 48-inch Schmidt. Its photographic plates also carry a human story: in 2002 astronomer Jean Mueller and eleven volunteers from the Mount Wilson Observatory Association and the Los Angeles Astronomical Society spent 13 weekends sleeving and boxing some 19,000 negatives for transport to Palomar, and Carolyn Shoemaker had asteroids named after the helpers.

The observatory sits on Palomar Mountain at roughly 5,500 feet (about 1,700 meters), where temperatures can be cool even in summer, so bringing an extra layer is a good idea. Visitors can see the telescope dome during daytime self-guided tours, though access to the inside of the dome is limited.

The instrument has no eyepiece, meaning it was never used for direct visual observation and works only as a camera that records the sky onto photographic plates. More than 19,000 of these glass plates from decades of observations are still kept at the observatory.