The Japanese tea ceremony (cha-no-yu, chadō, or sadō) is a traditional ritual influenced by Zen Buddhism in which powdered green tea, or matcha (抹茶), is ceremonially prepared by a skilled practitioner and served to a small group of guests in a tranquil setting.

Cha-no-yu (茶の湯, literally "hot water for tea"), usually refers to a single ceremony or ritual, while sadō or chadō (茶道, or "the way of tea") refer to the study or doctrine of tea ceremony. The pronunciation sadō is preferred by the Omotesenke tradition, while the pronunciation chadō is preferred by the Urasenke tradition.

Cha-ji (茶事) refers to a full tea ceremony with kaiseki (a light meal), usucha (thin tea) and koicha (thick tea), lasting approximately four hours. A chakai (茶会, literally "tea meeting") does not include a kaiseki meal.

Since a tea practitioner must be familiar with the production and types of tea, with kimono, calligraphy, flower arranging, ceramics, incense and a wide range of other disciplines and traditional arts in addition to his or her school's tea practices, the study of tea ceremony takes many years and often lasts a lifetime. Even to participate as a guest in a formal tea ceremony requires knowledge of the prescribed gestures and phrases expected of guests, the proper way to take tea and sweets, and general deportment in the tea room.

Two main schools, the Omotesenke (表千家) and Urasenke (裏千家), have evolved, each with its own prescribed rituals. A third school, Mushanokōjisenke, is largely unknown outside Japan. Currently, the Urasenke School is the most active and has the largest following, particularly outside Japan. Within each school there are sub-schools and branches, and in each school there are seasonal and temporal variations in the method of preparing and enjoying the tea, and in the types and forms of utensils and tea used.

All the schools, and most of the variations, however, have facets in common: at its most basic, the tea ceremony involves the preparation and serving of tea to a guest or guests. The following description applies to both Omotesenke and Urasenke, though there may be slight differences depending on the school and type of ceremony.

The host, male or female, wears a kimono, while guests may wear kimono or subdued formal wear. Tea ceremonies may take place outside (in which case some kind of seating will usually be provided for guests) or inside, either in a tea room or a tea house, but tea ceremonies can be performed nearly anywhere. Generally speaking, the longer and more formal the ceremony, and the more important the guests, the more likely the ceremony will be performed indoors, on tatami.

Both tea houses and tea rooms are usually small, a typical floor size being 4 1/2 tatami, or woven mats of straw, the traditional Japanese floor covering. The smallest tea room can be a mere two mats, and the size of the largest is determined only by the limits of its owner's resources. Building materials and decorations are deliberately simple and rustic.

If the tea is to be served in a separate tea house rather than a tea room, the guests will wait in a garden shelter until summoned by the host. They ritually purify themselves by washing their hands and rinsing their mouths from a small stone basin of water, and proceed through a simple garden along a roji, or "dewy path," to the tea house. Guests remove their shoes and enter the tea house through a small door, and proceed to the "tokonoma," or alcove, where they admire the scroll and/or other decorations placed therein and are then seated seiza style on the tatami in order of prestige.

Guests may be served a light, simple meal called a "kaiseki" (懐石) or "chakaiseki" (茶懐石), followed by sake, Japanese rice wine. They will then return to the waiting shelter until summoned again by the host.

If no meal is served, the host will proceed directly to the serving of a small sweet or sweets. Sweets are eaten from special paper called kaishi (懐紙); each guest carries his or her own, often in a decorative wallet. Kaishi is tucked into the breast of the kimono.

Each utensil - including the tea bowl (chawan), whisk (chasen), and tea scoop (chashaku) - is then ritually cleaned in the presence of the guests in a precise order and using prescribed motions. The utensils are placed in an exact arrangement according to the ritual being performed. When the ritual cleaning and preparation of the utensils is complete, the host will place a measured amount of green tea powder in the bowl and add the appropriate amount of hot water, then whisk the tea using set movements.

Conversation is kept to a minimum throughout. Guests relax and enjoy the atmosphere created by the sounds of the water and fire, the smell of the incense and tea, and the beauty and simplicity of the tea house and its seasonally appropriate decorations.

The bowl is then served to the guest of honour ("shokyaku" 初客, literally the "first guest"), either by the host or an assistant. Bows are exchanged between the host and guest of honour. The guest then bows to the second guest, and raises the bowl in a gesture of respect to the host. The guest rotates the bowl to avoid drinking from its front, takes a sip, murmurs the prescribed phrase, and then takes two or three more sips before wiping the rim, rotating the bowl to its original position, and passing it to the next guest with a bow. The procedure is repeated until all guests have taken tea from the same bowl, and the bowl is returned to the host. In some ceremonies, each guest will drink from an individual bowl, but the order of serving and drinking is the same.

If thick tea, koicha, has been served, the host will then prepare thin tea, or usucha, which is served in the same manner. In some ceremonies, however, only koicha or usucha is served.

After all the guests have taken tea, the host cleans the utensils in preparation for putting them away. The guest of honour will request that the host allow the guests to examine the utensils, and each guest in turn examines and admires each item, including the water scoop, the tea caddy, the tea scoop, the tea whisk, and, most importantly, the tea bowl. The items are treated with extreme care and reverence as they are frequently priceless, irreplaceable, handmade antiques, and guests often use a special brocaded cloth to handle them.

The host then collects the utensils, and the guests leave the tea house. The host bows from the door, and the ceremony is over. A tea ceremony can last between one hour and four to five hours, depending on the type of ceremony performed, and the types of meal and tea served.