红包的英文翻译为:red packet。
red packet:n.红包;
例:

(图片来自网络侵删)
Red packet containing a SURPRISE for each guest ( Limited amount only)!
当晚赠送免费红包惊喜(限量赠送)!
相关介绍Instead of a red envelope at Chinese New Year, he now got a year-end bonus.
农历年他没有拿到红包,现在反而拿到了年终奖金。
Every year on Spring Festival, my parents give me a red envelope.
每年的春节,我的父母都会给我一个红包。
New Year's morning, people put forward to refining the small lights, with a red packet, go to the elderly and their relatives and friends New Year.
元旦早上,人们提着精制的小灯,拿着红粉包,出门向老人和亲友拜年。