Taking a 3-month-old to Disneyland is safe and "do-able," but it requires a very different pace than a standard trip. At this age, babies have limited immune systems and haven't finished their full round of vaccinations, so it is vital to avoid extremely crowded indoor spaces and keep the baby shaded from the intense California or Florida sun. Disney is incredibly accommodating for infants, providing Baby Care Centers on Main Street with private nursing rooms, changing tables, and quiet areas for feeding. Many "slow" attractions like it's a small world, the Jungle Cruise, and the Disneyland Railroad allow you to hold your baby in your arms. However, the sensory environment—loud fireworks, bright lights, and high temperatures—can be overstimulating. Using a stroller with a fan and a UV cover is essential. As long as you utilize "Rider Switch" for the big thrills and prioritize the baby's feeding and nap schedule over seeing every attraction, it can be a magical, low-stress experience.