让我们欢乐吧（拉丁语：Gaudeamus igitur），又译“同欢”，又名De Brevitate Vitae（生活不足），是一首18世纪的拉丁文歌曲，歌词取材自1287年一篇手稿。因国际大学生体育联合会选用这首歌在****开幕式播放，升起国际大体联会旗，歌曲有时也被称为“国际大学生体育联合会会歌”。

这首歌曾是古欧洲大学的对酒歌曲，歌词反映一副享乐主义，音调轻松，得以广为流传。尽管这支曲子鼓励了纵情享受青春的人生态度，但也表现出了对于生与死的哲学性思考。今天是不少欧洲学校、大学、学生组织的官方代表歌曲，也在不少学院以此作为大学生的毕业歌。

"De Brevitate Vitae" and "Gaudeamus" redirect here. For the work by Seneca the Younger, see De Brevitate Vitae (Seneca). For the Gaudeamus Foundation and Prizes, see Gaudeamus Foundation. For the rodent genus, see Phiomyidae. For the 1928 Eliade novel, see Gaudeamus (novel).

"De Brevitate Vitae" (Latin: "On the Shortness of Life"), more commonly known as "Gaudeamus Igitur" ("So Let Us Rejoice") or just "Gaudeamus", is a popular academic commercium song in many Western countries, mainly sung or performed at university graduation ceremonies. Despite its use as a formal graduation hymn, it is a jocular, light-hearted composition that pokes fun at university life. The song is thought to originate in a Latin manuscript from 1287. It is in the tradition of carpe diem ("seize the day") with its exhortations to enjoy life. It was known as a beer-drinking song in many early universities and is the official song of many schools, colleges, universities, institutions, student societies and is the official anthem of the International University Sports Federation.