On a cruise to Mexico, your ability to drink at 18 depends entirely on whether you are on the ship or on Mexican soil. Once you step off the gangway in ports like Cozumel or Cabo San Lucas, Mexican law applies, which sets the legal drinking age at 18. You can legally purchase and consume alcohol at local bars, beach clubs, and restaurants. However, while on the ship, the cruise line's specific policy governs. Most major U.S.-based lines like Royal Caribbean, Carnival, and Princess maintain a strict minimum drinking age of 21 for all sailings originating in North America, even when the ship is docked in Mexico. Some lines may allow parents to sign a waiver for 18-to-20-year-olds to drink beer or wine on specific international itineraries, but this is increasingly rare for standard Mexican Riviera or Caribbean routes. In 2026, it is vital to carry a valid photo ID (like a driver's license) when heading into port, as Mexican establishments have become more consistent with age verification in high-traffic tourist zones.