| Eien | |
| Cover: | Eien single.jpg |
| Type: | single |
| Artist: | Zard |
| Album: | Eien |
| Released: | August 20, 1997 |
| Recorded: | February–June 1997 |
| Studio: | B.Gram-RECORDS |
| Genre: | |
| Label: | B-Gram Records |
| Producer: | Daiko Nagato, ZARD |
| Prev Title: | 'Kaze ga Toori Nukeru Machi he' |
| Prev Year: | 1997 |
| Next Title: | 'My Baby Grand ~Nukumori ga Hoshikute~~' |
| Next Year: | 1997 |
is Zard's[1] 22nd single released on August 20, 1997 under B-Gram Records label. Junichi Watanabe, the writer of the novel, wrote the title word "Eien" of the CD cover. The single reached rank number 1 first week. It charted for 13 weeks and sold 628,000 copies.[2] When Izumi Sakai died in 2007, it was selected as her fifth best song on the Oricon polls.[3]