Tsuchiya Koitsu (1870-1949) was a Japanese woodblock print artist, active in the 1930s and 1940s. He is considered to be part of the second generation of the Shin hanga artists, with the Shin hanga movement already well under way when he started designing woodblock prints. His recognition has grown during the past decades, and nowadays his prints are often compared to those of the likes of Hiroshi Yoshida and Kawase Hasui.

Tsuchiya Koitsu was born on August 28, 1870 under the name of Tsuchiya Sahei. His parents were farmers, but at age fifteen, he moved to Tokyo to become a trainee at a temple. Upon the recommendation of a priest he soon transferred to an engraving studio. Through connections of the studio he joined Kobayashi Kiyochika's residence as a pupil, and became strongly tied to the household of Kobayashi Kiyochika. Here he acquired the name "Koitsu", specialized in lithographs and published his first prints.

This lineage is significant in many ways. Kobayashi Kiyochika was a very accomplished ukiyo-e artist and a fore-runner for the later Shin hanga movement, even if he was not a part of it himself. He emphasized the role of lights and shadows and mood in his prints and is said to have exerted an influence on artists such as Kawase Hasui. Indeed, the interplay between light and shadow became an important part of Shin hanga woodblock prints and through his teacher, Tsuchiya Koitsu was well prepared to join the movement.

Another enabler for his later Shin hanga prints was unfortunately bad luck for Tsuchiya Koitsu, who experienced many personal hardships. Among these were health problems, which caused him to abandon his lithographic activities. To sustain himself, he made drawings for hanging scrolls for export to China. Unfortunately, little is known about his works in this area. Later, in 1931, publisher Watanabe Shozaburo, the driving force behind Shin hanga, held an exhibition commemorating the death of Kobayashi Kiyochika and was in contact with Tsuchiya Koitsu. Watanabe asked him to make a few designs for woodblock prints, which Watanabe ended up appraising highly.

Having entered the Shin hanga movement, Tsuchiya Koitsu went on to work with a multitude of woodblock print publishers, as was common at the time. The most important of these for him was without a doubt publisher Doi Hangaten, for whom Koitsu designed most of his woodblock prints. The president of Doi Hangaten, Doi Sadaichi, was committed to publishing high-quality woodblock prints and worked with excellent carvers and printers. Tsuchiya Koitsu mainly designed landscape prints there, and his work truly embodied the Shin hanga movement, excelling in the depiction of light and shadow, use of colors, expression of mood, and quality of printing, often requiring many woodblock impressions.

Because he joined the Shin hanga movement relatively late, Tsuchiya Koitsu missed important exhibitions in the United States in 1930 and 1936. With the advent of the war export stopped almost completely, resulting in Tsuchiya Koitsu being less known abroad than one might expect based on his body of work. In the last decades a rediscovery has taken place however, and Tsuchiya Koitsu is now considered as one of the foremost Shin hanga artists.