A major change in the 20th century was to shift from using solution to coat the glass with silver to using a vapor deposition process.

The observatory was founded in 1701 in Montee des Accoules (a location near Vieux Port, Marseille, France).

[4] In 1789 Jean-Louis Pons began work at Marseille Observatory as a doorkeeper, but he also received lessons in astronomy; by 1801 he had discovered his first comet.

[11] This led to a new building inaugurated by 1864, designed by the architect of Notre Dame de la Garde, also the 80 cm reflector was installed by that year[11] (at the Palais Longchamp site).

[16] Starting in 1990 Marseille Observatory had a study of H alpha (H-alpha (Hα)) in the southern galactic plane.

[17] This study used the 36 cm Marseille telescope at La Silla observatory in the southern hemisphere for data.

[18] In 1999 Marseilles Observatory published a study on simulating the formation of proto-planets and planetesimals with a large planetary body.

The facility includes two major technology platforms for qualification of space instruments and for fabrication and metrology of optical mirrors.

LAM astronomers specialize in cosmology and galaxy evolution, exoplanets and Solar System, and R&D in optics and instrumentation.

In 2012, the Observatoire Astronomique Marseille Provence merged with other earth-sciences research institutes from Aix-Marseille University and became a new entity called the Observatoire des Science de l'Univers Institut Pythéas (OSU-IP) which now includes 6 major labs for earth and universe sciences: CEREGE, IMBE, MIO, LAM.

The old Marseille Observatory site is a noted tourist attraction in the Palais Longchamp area.