No, you cannot take a 3-year-old to Disneyland for free. At the Disneyland Resort in California, Walt Disney World in Florida, and Disneyland Paris, the policy is that children under the age of 3 are admitted for free. Once a child turns 3 years old, they are required to have a valid theme park ticket for entry. For children aged 3 to 9, Disney offers a "Child" ticket, which is slightly discounted compared to the "Adult" ticket (required for everyone aged 10 and older). If your child is 3 or older, you will also need to ensure they have a theme park reservation if you are visiting during a period where reservations are required. While the entry is not free for a 3-year-old, many of the park's amenities, such as "Rider Switch" and certain entertainment, are specifically designed to accommodate families with young toddlers to ensure they still have a magical experience despite the ticket cost.