A transformer problem caused the late-morning outage in Toontown and Fantasyland, affecting 12 rides, park spokeswoman Suzi Brown said.
An unknown number of guests were taken off rides and no one was hurt.
Power was restored in Toontown and much of Fantasyland within a couple of hours. It was fully restored later in the afternoon, Brown said.
Mark Freeman of Provo, Utah, said he, his wife and two children were in the affected area when the power went out.
“We were in line for It’s A Small World,” he said. “It just went out. And they basically said, ‘Everything’s shut off.'”
Freeman and his family, who were at Disney as part of a three-day vacation, said they decided to go to nearby New Orleans Square to wait out the confusion.
“It was just such a mad house,” he said. “It was so crowded we couldn’t even get out of the park. We went and got ice cream and just sat there for probably a half-hour.”
Some people wondered on social media if they’d get refunds.
Guests are warned that all or part of the park may close without notice and tickets are nonrefundable in such cases. Brown said tickets may be refunded on a case-by-case basis because of the outage.