A courtesy name (Chinese:字, zi ), also known as style name, is a name bestowed upon one at adulthood in addition to one's given name. This practice is a tradition in East Asian cultures, including China, Japan, Korea, and Vietnam.

Formerly in China, the zi would replace a male's given name when he turned twenty, as a symbol of adulthood and respect. It could be given either by the parents or by the first personal teacher on the first day of family school.