For other events called Operation Avalanche, see Operation Avalanche.

Operation Avalanche was a major U.S. investigation of child pornography on the internet. Launched in 1999, it was made public in early August 2001 when over one hundred arrests were made. So many computers were confiscated during the raids that a backlog was created leading to a series of additional arrests over the next several years as more and more names of suspects were revealed. Followed in the United Kingdom by Operation Ore.