Yes, you can bring a Yeti cooler or tumbler on a plane, but its use depends on size and contents. Most Yeti drinkware (like Ramblers) is permitted in your carry-on, provided it is empty when passing through security to comply with 3-1-1 liquid rules. For Yeti coolers, soft-sided models like the Hopper series are popular carry-ons because they fit under seats or in overhead bins. Large, hard-sided coolers (like the Tundra) generally must be checked as oversized baggage due to their dimensions. If you are using the cooler to transport perishables, TSA regulations allow frozen ice packs or dry ice (up to 5.5 lbs in a vented container), but any ice packs must be frozen solid at the checkpoint. If they are slushy or melting, they may be confiscated. Always check your specific airline's weight limits, as Yeti's robust construction makes them heavier than standard luggage even when empty.