Los Angeles police Sgt. Keith Green said Monday that Jenner filed a police report of assault with a deadly weapon after being hit early Sunday outside the popular nightspot.
Green says Jenner was not given medical help and no one was arrested.
Green could not confirm Lavigne's involvement, but on her Twitter account, she said she "got attacked by 5 people last night out of nowhere. Not cool."
Jenner is the son of Olympian Bruce Jenner and a regular on MTV's "The Hills." He's also a stepbrother of the Kardashian sisters and has appeared on their reality show.