Johann Gottfried Galle (9 June 1812 – 10 July 1910) was a German astronomer from Radis, Germany, at the Berlin Observatory who, on 23 September 1846, with the assistance of student Heinrich Louis d'Arrest, was the first person to view the planet Neptune and know what he was looking at.

The discovery of Neptune is widely regarded as a dramatic validation of celestial mechanics, and is one of the most remarkable moments of 19th-century science.

The very same night (after Encke gave permission to search, against his own judgement), in collaboration with his assistant Heinrich Louis d'Arrest, Galle discovered a star of 8th magnitude, only 1° away from the calculated position, which was not recorded in the Berliner Akademischen Sternkarte.

Over the next two evenings, a proper motion of the celestial object of 4 seconds of arc was measured, which determined it absolutely as a planet, for which Le Verrier proposed the name Neptune.

Before the enacted nomination from Friedrich Wilhelm IV effected de facto, Galle withdrew his application at the beginning of 1848 due to an intrigue against him led by Carl Gustav Jacob Jacobi.

[4] At Breslau he dealt with the exact determination of planetary orbits and developed methods for calculating the height of the aurorae and the path of meteors, and consolidated the data for all 414 comets discovered up to 1894 into one work (with the help of his son).

Two craters, one on the Moon and the "happy face" one on Mars, the asteroid 2097 Galle, and a ring of Neptune have been named in his honor.