| Orbital Period | |
| Type: | Album |
| Artist: | Bump of Chicken |
| Cover: | Orbital Period (Bump of Chicken album - cover art).jpg |
| Released: | December 19, 2007 |
| Recorded: | 2005–2007 |
| Length: | 70:59 (without hidden track) |
| Label: | Toy's Factory TFCC-86245 |
| Prev Title: | Yggdrasil |
| Prev Year: | 2004 |
| Next Title: | Present from You |
| Next Year: | 2008 |
Orbital Period is the fifth studio album by Bump of Chicken, released on December 19, 2007. The album features the singles "Planetarium", "Supernova/Karma", "Namida no Furusato", "Hana no Na", and "Mayday". Orbital period became the best-selling album two days in a row at debut, according to Oricon Style. It was the second best-selling album on its debut week.[1]