According to Ryanair’s 2026 safety regulations, you can and must bring your vaping devices and e-cigarettes in your carry-on baggage or on your person. They are strictly prohibited from checked-in luggage because they contain lithium batteries, which pose a fire risk in the aircraft's cargo hold. While you are allowed to carry the device, the use of vapes or e-cigarettes is strictly prohibited at any time during the flight; doing so can trigger smoke alarms and lead to significant fines or removal from the aircraft. Regarding e-liquids, they are subject to the standard "liquids rule," meaning each container must be 100ml or less and fit within a single, transparent, resealable 1-liter plastic bag. If your vape has a removable battery, it must be protected to prevent short circuits. It is also wise to ensure the tank is not completely full, as changes in cabin pressure during ascent can cause the liquid to leak into your bag.