Hey there, Jo, and welcome to planDisney! Thanks so much for stopping by with your question.
Great news - yes, you can absolutely leave the park and return on the same day! All you need is your
theme park ticket with the
park reservation for that day. This is called re-entry, and it's something my family takes advantage of pretty regularly. When you're visiting with young kids like I am, an afternoon break back at the hotel to rest and recharge before heading back in for the evening can honestly make or break the whole day. Our kiddos are much better company for the nighttime shows when they've had a little downtime in the middle of the afternoon!
Keep in mind that once you fully leave the Disneyland Resort area, you will need to come back through the security screening area when you return, but there are otherwise no barriers to leaving and returning the parks on the same day.
In my experience, the parks often feel their busiest around mid-afternoon, so as I mentioned, my family and I like to take those afternoon breaks where we go back to our hotel and rest, or enjoy the pool so that we're primed and ready to go as late as possible into the evening.
As you continue to plan your trip, make sure to also keep an eye on the
Disney Parks Blog. It has a lot of really helpful articles about all the fun extras that are happening around the Happiest Place on Earth. My favorite articles are the
Foodie Guides, which cover all the delicious seasonal snack and drink offerings available around the resort.
Thanks again for your question, Jo! I hope you have a fun time on your upcoming visit.
Have a Magical Day,
Greg