Kourtney Kardashian celebrated big the year before her big 4-0 ... at the happiest place on earth.
The 39-year-old and her extended brood hit up Disneyland Saturday. Boyfriend Younes Bendjima, Kris Jenner, Corey Gamble, Mason and Penelope jumped on ride after ride and all clearly had a blast.
No sign of Kim, Kylie or Kendall. Khloe is still in Cleveland, although next week could provide telltale clues on whether she and Tristan Thompson are history ... if she flies back to L.A. with daughter True.