Ark är det sjätte albumet av L'Arc-en-Ciel. Det gavs ut 1 juli 1999 på Ki/oon Records. Albumet släpptes samtidigt som "Ray".
Låtlista
| Nr | Titel | Text | Musik |
|---|
| 1 | Forbidden Lover | Hyde | Ken |
| 2 | Heaven's Drive | Hyde | Hyde |
| 3 | Driver's High | Hyde | Tetsu |
| 4 | Cradle | Hyde | Yukihiro |
| 5 | Dive to Blue | Hyde | Tetsu |
| 6 | Larva | ‐ | Yukihiro |
| 7 | Butterfly's Sleep | Hyde | Ken |
| 8 | Perfect Blue | Tetsu | Tetsu |
| 9 | Shinjitsu to Gensou to (真実と幻想と, Med Sanningen och Fantasin?) | Hyde | Ken |
| 10 | What is Love | Hyde | Tetsu |
| 11 | Pieces [Ark Mix] | Hyde | Tetsu |
DVD Låtlista (15th Anniversary Expanded Edition)
| Nr | Titel |
|---|
| 1 | Making of the "Forbidden Lover" Music Video |
| 2 | Recollection 1 |
| 3 | Making of the "Heaven's Drive" Music Video |
| 4 | Recollection 2 |
| 5 | Butterfly's Sleep@London Hearts (ロンドンハーツ) * (1999.6.20 O.A.) |
| 6 | Making of the "Driver's High" Music Video |
| 7 | Recollection 3 |
| 8 | Making of the "Pieces" Music Video |
| 9 | Recollection 4 |
| 10 | Documentary on "1999 Grand Cross Tour" (1999.8.20) |
* Japanskt komedi TV-program.