(Monza, Province of Milan 1857 - Bordighera, Province of Imperia, 1927) was an Italian painter.
The nephew of Mose Bianchi, Mariani abandoned a career in banking to devote himself entirely to painting. His apprenticeship began in 1879 under the guidance of the painter Eleuterio Pagliano, who introduced him to life studies. A trip to Egypt with Uberto DelleOrto in 1881 provided subjects for the works shown at the Brera exhibitions of the next two years. He focused on landscape painting and began to specialise in seascapes in 1883, when he first stayed on the coast of Liguria. The first views of the Zelata area outside Pavia appeared in 1894. His art is characterised by subtle sensitivity in the investigation of the reflection of light on water, captured in different seasons and times of the day to achieve highly atmospheric effects. In was at the beginning of the new century that he began to combine naturalistic landscapes with depictions of the elegant world of high society in fashionable gatherings and cafes. His vast production of landscapes and portraits was regularly presented at the major national and international exhibitions and won numerous official awards.