Many happy returns 是個賀詞，意為「(祝你) 生日快樂，長命百歲」。這個片語為 many happy returns of the day 的縮略，自 1789 年開始使用至今，原本用在其他賀詞之後來表示「年年有今日，歲歲有今朝」的意思，如 “Merry Christmas/Happy New Year/Happy Anniversary, many happy returns.” (聖誕節快樂/新年快樂/週年紀念日快樂，祝你年年有今日，歲歲有今朝)。不過，它現在主要用來祝賀生日快樂，相當於 Happy Birthday。
例句：
- I came by to wish you many happy returns. (我來此祝你生日快樂)
- Happy 80th birthday, Grandpa, and many happy returns! (爺爺，80 歲生日快樂，祝你福如東海，壽比南山！)
- Most of the students will want to wish many happy returns of the day to Professor Liao on his 46th birthday. (大部分學生都會想要在廖教授 46 歲生日時向他祝賀生日快樂)