Kylie Jenner's Birthday Bash About to Take Off for Italy

Kylie Jenner's about to take off with a private jet full of family and close friends to begin her birthday celebration, and "hubby" Travis Scott is joining the festivities ... TMZ has learned.

Kylie and Travis will be celebrating her 22nd birthday off the coast of Italy, and it's gonna be a full flight over there Tuesday afternoon. Our Kardashian-Jenner sources tell us Kris Jenner and Corey Gamble will be on board along with Kylie's assistant, Victoria, and her pals, Stassi Karanikolaou and Yris Palmer.

Never one to miss a party ... we're told Scott Disick and his GF, Sofia Richie, will also be on the flight. As for where they're all headed -- TMZ broke the story, Kylie will ring in 22 on the $250 million megayacht, "Tranquility."

The ship comes with a staff of 29 and every possible amenity you can imagine: sauna, helipad, theater, swimming pool and even a beauty salon.

The super-dinghy normally rents for $1.2 million per week.

Interestingly, none of Kylie's sisters are on the flight tomorrow -- but remember, Kourtney's been vacationing in Europe since last week. Seems likely she'll join the party. As for the other sisters, they travel at the drop of a dime, so stay tuned.