Howdy, Jessica! Thanks for bringing your question to planDisney!
My family and I almost always take mid-day breaks when we visit the parks! We usually start our days early and want to refresh before we head back into the parks for dinner and nighttime entertainment. So, you can absolutely leave the parks to head back to your hotel and come back later in the day. You can also leave the parks to visit the
Downtown Disney District to shop and eat and reenter the parks afterward.
The only caveat to reentry is if the parks happen to reach capacity--which means that no guests will be allowed to enter until enough people leave the parks that it is safe to let more people in. Luckily, it is extremely rare that the parks hit capacity, especially since they implemented the new
theme park reservation system. But if you happen to be visiting on popular days like Christmas or New Year's Eve, then I wanted to let you know about this possibility just in case.
I hope your visit to the Disneyland Resort is full of magic and memories!
-Linda