Named after the church and rue Saint-Ambroise, which honour Ambrose of Milan.
Ambrose (about 340–397) was bishop of Milan from 374. The first Saint-Ambroise church was the chapel of the Annonciades convent, built in 1659; the present church, by Théodore Ballu, dates from 1863–1868 and gave its name to the quarter. The rue Saint-Ambroise, opened in 1783 on the convent's site, was first the rue des Annonciades and was renamed in 1802.