Amanda Knox thinks her infamous murder case over in Italy is all one big joke … at least if you listen to her new standup routine.

Foxy Knoxy poked fun at her Italian nightmare during a recent gig at the Tacoma Comedy Club in Washington … joking that motherhood is a lot harder than being locked up in an Italian jail.

As you know … Amanda was a Seattle college student studying abroad in 2007 when she and her Italian boyfriend of a week were thrown behind bars for the rape and murder of her British roommate, Meredith Kercher.

Amanda was ultimately acquitted — as was her then-BF Raffaele Sollecito — after spending 4 years in prison.

In her standup routine, Amanda points out she also spent 4 years producing the Hulu show “The Twisted Tale of Amanda Knox,” and has been a mom for 4 years … and says of all three life phases, being a mom has been the toughest.

Amanda uses her daughter in another joke … she says when they go to the playground, her kid plays a game called “Mommy goes to Italy,” which consists of her child holding on to the jungle gym bars and screaming, “Let me out!!!”