Regiomontanus-Sternwarte, Public observatory in Nuremberg, Germany.

The Regiomontanus-Sternwarte Nürnberg is a public observatory on the Rechenberg in the St. Jobst district, at about 338 m above sea level. Its dome houses a 60 cm main telescope also used for research, and 25 telescopes are available in total. A 3 m radio telescope, the Arno-Penzias-Radioteleskop, stands on the site.

The current observatory on the Rechenberg was designed by architect Paul Seegy and opened in 1931. After World War II it was severely damaged by looting and later repaired. In 2004 the Rotary Clubs of Nuremberg funded a full renovation, adding a 60 cm main telescope and expanding the library; on that occasion asteroid 3825 was named Nürnberg.

The observatory is named after Johannes Müller, called Regiomontanus after Königsberg in Bavaria, who observed the sky from Nuremberg in the 15th century. That private station had no link to today's observatory beyond the name. Volunteers of the Nürnberger Astronomische Arbeitsgemeinschaft run over 50 events a year, including lectures and guided telescope viewing.

The observatory is accessible and visitors can spend time using the telescopes and attending guided sessions. Clear nights offer the best viewing conditions, so checking the weather before your visit helps ensure a good experience.

On 26 April 2019 a 3-metre radio telescope was handed over to the public, named after Nobel laureate Arno Penzias (1933–2024); Bavarian minister-president Markus Söder attended the ceremony. The name also recalls the difficult childhood Penzias endured. It widened the observatory's educational programme beyond optical observing.