No, you do not need a reservation. On Disney Cruise Line, at least one sit down restaurant is typically open for lunch each day, and it does not require a reservation.
The open lunch option will be listed in the Disney Cruise Line app, so you can easily see which dining room is serving lunch that day and what time it opens. You can simply walk in during operating hours and be seated.
This is a great alternative if you want a quieter, more relaxed meal away from the bustle of the buffet. The dining rooms are air conditioned, less crowded, and offer table service, which can be especially nice on busy sea days.
The tradeoff is time. A sit down lunch takes longer than grabbing food from the buffet, so if you are eager to get back to pool time, shows, or other activities, the buffet may be faster. Still, if you are looking for a calmer lunch experience without needing to plan ahead, the main dining room is an easy and often overlooked option.
