The Blink-182 drummer and Poosh founder are reportedly set to marry in a lavish ceremony at Castello Brown, a 16th century castle in the picturesque seaside town of Portofino, this weekend.
The family trip comes just days after the pair confirmed they had legally married at a courthouse in Santa Barbara, California.
The intimate nuptials were attended by Barker’s father, Randy, and Kardashian’s grandmother, Mary Jo Campbell.
On Friday evening the couple were pictured heading out for dinner in the Italian village with Kardashian’s famous family.
Photographs showed the bride-to-be arriving at the eatery in a sheer red Dolce & Gabbana dress, which she wore with a matching fur stole and lace-up heeled sandals.
Meanwhile, Barker opted for a black tweed jacket that he wore open to reveal his tattooed torso, with black trousers and sunglasses.
They were joined by Barker’s daughter, Alabama, 16, and Kardashian’s children, Mason, 12, Penelope, 9, and Reign, 7.
Kardashian’s sisters, Kim, Khloe, Kendall and Kylie were also present, as well as her mother, Kris Jenner, and Kim’s daughter, North, 8.
Scott Disick, Kardashian’s ex-partner with whom she shares her children, was notably absent.
Most of the party appeared to be wearing ensembles from Dolce & Gabbana.
Kendall donned a black satin corset, worn with a sheer knee-skimming skirt as she walked hand-in-hand with her boyfriend, basketball player Devin Booker.
She accessorised with a black choker bearing a large bejewelled red cross.
Kylie was photographed in a black Dolce & Gabbana mini dress, which she wore with black and white boots and a matching handbag.
Khloe arrived in a figure-hugging leopard-print gown which swept the ground as she walked. She accessorised with black heeled sandals and large gold cross-shaped earrings.
Kim appeared to be the only one of her sisters who didn’t wear Dolce & Gabbana for the evening, stepping out in a cut-out catsuit that bared her midriff.
Meanwhile, Kris opted for a black Dolce & Gabbana dress with a fish net overlay and lace trims.
According to TMZ, the guests are set to enjoy four days of festivities in Italy, before celebrating at another reception in Los Angeles at a later date.
Barker and Kardashian have been extremely tight-lipped about their wedding plans, with Kris Jenner recently revealing that she has been “sworn to secrecy” regarding the details of the upcoming events.
Speaking to People, Jenner said she would “get in so much trouble” if she talked about her eldest daughter’s upcoming wedding.
“I’m just gonna sit in the background,” she said. “And not say a word because I don’t want to get in trouble.”