Gyokuro (Japanese: 玉露; "jade dew") is a type of green tea from Japan. It differs from the standard sencha (a classic green tea grown in the sun) in being grown under the shade rather than the full sun. The name "gyokuro" translates as "jewel dew" (or "jade dew"). According to the Japan Tea Central Association, gyokuro is defined as "a tea manufactured in the same manner as sencha from tea leaves picked from covered tea gardens that are almost completely shaded from sunlight for about 20 days using covering materials such as reed screens, straw, or shading nets, from the time when the new shoots of the first flush start to grow."

While most sencha is from the Yabukita (薮北) cultivar of Camellia sinensis, gyokuro is often made from a specialised variety such as Asahi, Okumidori, Yamakai, and Saemidori. Most gyokuro is grown in the Fukuoka, Kyoto, and Mie prefectures.

Gyokuro tea production dates back to the 1830s, when the merchant Yamamoto Kahei discovered some Japanese farmers were covering tea plants with a netting to protect them from frost, and that this actually changed the flavour and aroma of the tea. He introduced the tea to Edo and it was immediately popular.

Though it is categorised as a type of sencha according to production methods, gyokuro cultivation differs from other sencha teas. Gyokuro tea leaves are shielded from the sun before being harvested. The period can vary from twenty to thirty days. Three weeks / twenty days is a standard length of time for a tea to be considered gyokuro proper. Anything shaded for under twenty days is considered kabuse tea.

The shading causes both the amino acid L-theanine and the alkaloid caffeine in the tea leaves to increase, and the catechins and tannins to decrease, which yields significant differences from the flavour of sencha. The shading causes the plant to stop converting theanine into catechins to protect itself from UV light. Furthermore, the stress of shading also makes the plant produce more caffeine to protect itself. Gyokuro also has higher chlorophyll content, which accounts for the dark green colour of the leaves. These chemical differences lead to unique flavour and aroma of the tea, giving it more umami, a savory sweetness, and less bitterness and astringency. The increased L-theanine content elicits the increased umami taste of gyokuro. It also produces a calming effect which balances out the high caffeine content of gyokuro. Studies on L-theanine indicate that it may also help reduce stress and anxiety and may have neuroprotective effects.

The length and type of shading or covering (kabuse) will affect the taste of the gyokuro tea. Shading may be done with a scaffolding built over the tea field or by covering the plants directly with the shading material (jikagise). The opacity of the shading material (which can be synthetic, straw, or reed) will also affect how much theanine is contained in the leaves, which affects the flavour, particularly umami. The process is often done in stages, initially blocking 70% of the sunlight, and ramping up to 80 and 90 percent before harvesting. The higher grades of gyokuro are shaded more extensively and for longer times.

The processing of the picked gyokuro leaves will also affect the aroma and taste of the tea. Like standard sencha, gyokuro is steamed after harvesting, usually in industrial machinery. The length of the steaming can be short (asamushi), middling (chumushi), or long (fukamushi, 1–2 minutes). This will also affect the aroma and flavour of the tea. After steaming, the leaves are then dried and rolled, traditionally by hand, but now it is common to use industrial machinery to roll the leaves.

If the leaves were harvested mechanically, the stems and other parts of the plant must be separated out from the leaves. Hand picked gyokuro exists, but it commands higher prices.