| January | |
| 01 | L'A HAPPY NEW YEAR！ Makuhari Messe International Exhibition Center 9-11 |
| May | |
| 28-29 | 20th L'Anniversary LIVE Ajinomoto Stadium Simultaneously broadcast to 40 theaters in Japan and in 6 cities abroad (Paris、London、New York、Taiwan、Hong Kong、Seoul) |
| June | |
| 24 | TV Performance TV Asahi's「MUSIC STATION」 |
| 28 | Nico Nico Douga Nico Nico Broadcasting 24-hour site-jacking&live performance |
| 29 | First single of the 20th anniversary year "GOOD LUCK MY WAY" (37th Single) released! (Theme song to the film "Fullmetal Alchemist: The Sacred Star of Milos") |
| July | |
| 21 | L'Arcafe L'Arc～en～Ciel × SPACE SHOWER TV THE DINER exhibit (until 8/31) |
| September | |
| 10-11 | 20th L'Anniversary TOUR start Saitama Super Arena |
| 17-18 | 20th L'Anniversary TOUR Marine Messe Fukuoka |
| 23 | TV Asahi Dream Festival Nihon Budokan Performance |
| October | |
| 01-02 | 20th L'Anniversary TOUR Sapporo Kitayell |
| 12 | Second single of the 20th anniversary year "X X X"(38th Single)Released ☆Debuted at No. 1 on Oricon |
| 14 | TV Performance TV Asahi's 「MUSIC STATION」 |
| November | Scenes from 20th L'Anniversary LIVE shown on 20 screens abroad (Singapore、France、Indonesia、America、United Kingdom) |
| 02-03 | 20th L'Anniversary TOUR Nagoya Nagoya Civic General Gymnasium |
| 30 | TV Performance Nihon TV "Nihon TV Music Festival Best Artist 2011" |
| December | |
| 03-04 | 20th L'Anniversary TOUR Kyocera Dome Osaka Simultaneously broadcast to 54 movie theaters in Japan plus Taiwan、Hong Kong、and Korea |
| 21 | Third single of the 20th anniversary year "CHASE" (39th Single) Released ☆Debuted at No. 2 on Oricon |
| 23 | TV Performance - TV Asahi's "MUSIC STATION SUPER LIVE 2011" |
| 31 | TV Performance NHK's 62nd Annual Kōhaku Uta Gassen |
