Yes, a 17-year-old can absolutely go to Disneyland alone. Disney’s official policy for both Disneyland Resort in California and Walt Disney World in Florida states that children aged 14 and older are permitted to enter the parks without an adult. Children under 14 must be accompanied by someone age 14 or older to enter. This means a 17-year-old is legally allowed to purchase their own ticket (though they may need a parent's credit card), make their own theme park reservations, and navigate the parks independently. They can also supervise younger siblings who are at least 3 years old. In 2026, while they can enter the park alone, they should still carry a valid ID and have a way to contact their parents. It is also worth noting that while they can enjoy the rides, they must be 18 to check into most Disney resort hotels on their own. For the park experience itself, a 17-year-old is treated as an "adult" in terms of ticket pricing and park privileges, giving them full freedom to explore the "Happiest Place on Earth" solo.