Ahoy, and welcome to planDisney, Jason! If you love cruising as much as I do, I know a trip to the Most Magical Place on Earth is like a spoonful of sugar to make the cruise "goodbye" go down in the most delightful way.
If you pack light, your best option to store your luggage for a day at
Magic Kingdom Park might be the lockers near Main Street, U.S.A. There are "
jumbo lockers" available. These lockers measure 17"x 22"x 26" and can typically hold a carry-on bag and a small duffel. These lockers are inside the gates, so your bags must be no larger than 24"x 15"x 18" to be carried into the theme park. The bags will also be subject to search, so you may want to read the list of
prohibited items to make sure there will be no issues getting through security.
If you have a little more in tow, you might look into the luggage storage options at the Orlando airport, including how early you can check your bags with your airline or the companies that provide onsite storage. If you have transportation arranged with your cruise line back to the airport, these may be the easiest options to explore. Then you can leave your luggage behind, hail a ride to Magic Kingdom and spend some time in the shadow of
Cinderella Castle before the clock strikes 12 and the return to reality abruptly interrupts the magic.
Jason, I hope your vacation by sea and land is practically perfect in every way. If we can help with any future questions, please sail back by
planDisney.
See and SEA 'Ya Real Soon!
Jana