Osechi-ryōri (御節料理, お節料理 or おせち) are traditional Japanese New Year foods. Osechi are easily recognizable by their special boxes called jūbako (重箱), which resemble bentō boxes. Like bentō boxes, jūbako are often kept stacked before and after use. Not all parts of Japan, such as Suzu in Ishikawa, practice the custom of eating osechi.

Osechi is a food eaten to wish the family good health for the year, and the various dishes that make up osechi have their own roles to bring good luck in terms of longevity, prosperity of descendants, a bountiful harvest, success in life, and financial success.

Originally, osechi was rice served high in a bowl to celebrate the five annual ceremonies (gosekku) from the Nara (610-794) to Kamakura periods (1185-1333). Osechi is influenced by the ritual of naorai (also known as kyōshoku), in which a person who prays eats with the Shinto kami. The old custom of offering osechi to the toshigami (Shinto deity) on the kamidana (household Shinto altar) before eating it with the family is a remnant of this ceremony.

Osechi changed greatly under the influence of honzen-ryōri, a banquet dish that was ritualized in daimyo (feudal lords) and the samurai society during the Muromachi period (1336-1573). Many of the standard dishes that make up osechi today are derived from honzen-ryōri.

During the Edo period (1603-1868), osechi came to refer only to New Year's dishes. With the economic development of Japanese society, the custom of osechi spread to the general public, the chōnin class, and a new custom began. From the late Edo period, some of the dishes in osechi began to be packed in jūbako, and from the Meiji era (1868-1912) to the Showa era (1912-1989), the variety of dishes packed in jūbako increased, becoming a luxurious product sold in department stores. Kohaku Namasu is served as part of the Osechi New Year spread.

The dishes that make up osechi each have a special meaning celebrating the New Year. Some examples are:

The term osechi is derived from the term o-setchiku (御節供), which originally referred to annual imperial court events and the food served at these events. New Year's Day was one of the five annual ceremonies (gosekku) in the Imperial Court in Kyoto. This custom of celebrating particular days was introduced from China into Japan.

The osechi of the Nara (710–794) and Heian periods (794–1185) were quite different from those of today. Osechi of those periods consisted of rice served high in bowls that the emperor served to court officials on the five annual ceremonies of the year. The officials would ceremonially eat a small portion of the rice at court and then take it home to eat with their families. Osechi is believed to have been influenced by the Shinto ritual of naorai (kyōshoku). Naorai is a ritual of eating with the kami in order to offer prayers to them. Examples of this ritual are the emperor's enthronement ceremony, Daijōsai, and the old custom of eating osechi after offering it to the altar of the kamidana (household Shinto altar).