Stroke order (simplified Chinese: 笔顺; traditional Chinese: 筆順; pinyin: bǐshùn; Japanese: 筆順 hitsujun or 書き順 kaki-jun; Korean: 필순 筆順 pilsun or 획순 畫順 hoeksun) refers to the order in which the strokes of a Chinese character are written. A stroke is a movement of a writing instrument on a writing surface. Chinese characters are used in various forms in Chinese, Japanese, Korean, and in Vietnamese. They are known as Hanzi in Chinese, Kanji in Japanese, Hanja in Korean, and Hán tự in Vietnamese.

Because most Chinese characters have many strokes, certain stroke orders were recommended to ensure speed, accuracy, and legibility in composition. In the twentieth century, simplification of Chinese characters took place in mainland China, greatly reducing the number of strokes in some characters, and a similar but more moderate simplification also took place in Japan. In some cases the character was unchanged, but the stroke order changed; the basic rules of stroke order within each region, however, remained the same. Because writing characters in the official stroke order can greatly facilitate learning and memorization, children are required to learn and use it in school; adults, however, may ignore or forget it for certain characters, or develop idiosyncratic ways of writing. While this is rarely a problem in day-to-day writing, incorrectly ordered or written strokes can produce illegible or incorrect characters. Also, the accuracy of handwriting recognition software may be reduced when entering strokes out of order.