Nihonga (Japanese: 日本画) is a Japanese style of painting that typically uses mineral pigments, and occasionally ink, together with other organic pigments on silk or paper. The term was coined during the Meiji period (1868–1912) to differentiate it from its counterpart, known as Yōga (洋画) or Western-style painting. The term translates to "pictures in a Japanese style."

In the narrow sense, it refers to paintings that were developed during the 77 years from the Meiji Restoration to the end of World War II based on traditional Japanese techniques and styles, such as calligraphy and hand-painted painting , rather than oil painting. In contrast, oil paintings were called Yōga.

In a broader sense, the term can be extended to include works made before the Meiji Restoration and after World War II. In such cases, the term is often used with some ambiguity as to whether it refers to works that have Japanese characteristics in terms of subject matter or style despite being of Chinese origin, or whether it refers generally to drawings made in Japan before the arrival of oil painting techniques.

The former, Meiji-era Nihonga, began when Okakura Tenshin and Ernest Fenollosa sought to revive traditional Japanese painting in response to the rise of a new Western painting style, Yōga. Hashimoto Gahō, a painter of the Kano School, was the founder of the practical side of this revival movement. He did not simply paint Japanese-style paintings using traditional techniques, but revolutionized traditional Japanese painting by incorporating the perspective of Yōga and set the direction for the later Nihonga movement. As the first professor at the Tokyo Fine Arts School (now Tokyo University of the Arts), he trained many painters who would later be considered Nihonga masters, including Yokoyama Taikan, Shimomura Kanzan, Hishida Shunsō, and Kawai Gyokudō.

The term was already in use in the 1880s and a discussion of the context at the end of the Edo period is traced in Foxwell's monograph on Making Modern: Japanese-style Painting. Prior to then, from the early modern period on, paintings were classified by school: the Kanō school, the Maruyama-Shijō school, and the Tosa school of the yamato-e genre, for example.

At about the time that the Tokyo Fine Arts School was founded, in 1887, art organizations began to form and to hold exhibitions. Through them, artists influenced each other, and the earlier schools merged and blended. With the additional influence of Western painting, today's nihonga emerged and developed.

Nihonga has gone through many phases of development since the Meiji period. The impetus for reinvigorating traditional painting by developing a more modern Japanese style came largely from many artist/educators, which included Shiokawa Bunrin, Kōno Bairei, Tomioka Tessai and art critics Okakura Tenshin and Ernest Fenollosa, who attempted to combat Meiji Japan's infatuation with Western culture by emphasizing to the Japanese the importance and beauty of native Japanese traditional arts. These two art critics, and in particular Tenshin who was called the father of modern Japanese art, championed the preservation of traditional art with innovation and synthesis with Western-style painting. Nihonga was thus not simply a continuation of older painting traditions viewed in this light. Moreover, stylistic and technical elements from several traditional schools, such as the Kanō-ha, Rinpa and Maruyama Ōkyo were blended together.

Some Western painting techniques were adopted, such as perspective and shading, in a bid to move away from the importance of the painted line from East Asian painting tradition. Because of this tendency to synthesize, it has become increasingly difficult to draw a distinct separation in either techniques or materials between Nihonga and Yōga.