红包，亦称红封包，粤语中称为利是（粤语口语音又作励事，俗写作利是、利事），越南语也称为利是，是将金钱放置红色封套内做成的一种小礼物。送红包是中国、越南传统习俗。最常见的是在各种喜庆场合，例如新春、婚礼、生辰等致送金钱作为礼物时都会使用。红色在中国文化内代表喜庆。红包内一般会放入有吉祥数字的金钱，例如有8字，或以双数结尾的数目。

传统的红包是以一张红纸包裹金钱。但近年在很多地方都已改用机器印制的红包袋。每年临近春节前，各大商业机构都有制作红包派发给顾客。

In Chinese and other East Asian societies, a red envelope, red packet, lai see (Cantonese), ang pao (Hokkien) or hong bao (Mandarin) is a monetary gift which is given during holidays or special occasions such as weddings, graduation or the birth of a baby. Outside of China, similar customs exist across parts of South East Asia and many other countries with a sizable ethnic Chinese population.