Bring a large pot of salted water to a boil. Add the elbow macaroni and cook until just al dente, about 8 minutes. Drain and rinse under cold water until completely cooled, then transfer to a large mixing bowl.
Add the chopped celery, diced onions, grated carrots, and drained pineapple to the cooled pasta. Mix gently to combine all the colorful ingredients evenly.
Pour in the mayonnaise and drizzle the apple cider vinegar over the mixture. Stir everything together until the pasta and vegetables are evenly coated with the creamy dressing.
Season with salt and pepper to taste. Taste and adjust the mayo or vinegar if needed to balance the flavors.
Cover the bowl with plastic wrap and refrigerate for at least 30 minutes, or up to 24 hours, to allow flavors to meld and the salad to chill thoroughly.
Before serving, give the salad a good stir, and if it has thickened, fold in a splash of milk or water to loosen the texture slightly. Serve chilled and enjoy the bright, crunchy, and creamy Hawaiian Macaroni Salad.