La Voix lactée, Contemporary mosaic in Saint-Lazare metro station, Paris, France

La Voix lactée is a glass mosaic by Quebec artist Geneviève Cadieux, installed in 2011 at the north end of the tunnel linking line 14 to line 9 at Saint-Lazare station. It fills an arched wall panel shaped as a portion of a disc, showing a close-up of two parted lips in red, orange and brown tesserae split by a dark jagged line. Verses by Anne Hébert, also in mosaic, line the tunnel walls leading to it.

In 1966 the RATP lent a Guimard entrance to the Montreal transport authority, which installed it at Square-Victoria–OACI station. After its restoration, the entrance was given permanently to Montreal in 2003, and in exchange Montreal promised Paris a work of art. A 2009 competition on the theme of the French language selected Geneviève Cadieux's project, inaugurated on 4 October 2011.

The mosaic takes its title from a homophone of La Voie lactée, the Milky Way, echoing the name of Cadieux's earlier photographic work on the roof of the Montreal Museum of Contemporary Art. In the tunnel leading to the lips, verses by Quebec poet Anne Hébert are set in mosaic, so travellers read her lines before reaching the mouth.

The mosaic is located at the north end of the connecting tunnel between lines 14 and 9, making it easy to view while transferring between trains. Visitors can see the work during regular metro hours without any need for special access or entry requirements.

The mosaic is a reproduction of a photograph that was originally displayed at the Montreal Museum of Contemporary Art, recreated as glass mosaic by the German workshop Franz Mayer. This transformation from photographic image to glass mosaic gives the artwork a completely different tactile quality and visual presence in the tunnel space.