YouTube says it is fixing an error which outage monitoring website DownDetector said has affected about 286,000 users.
The issue started about 12:53pm on Thursday (NZDT).
Users were able to access the YouTube website, but videos were failing to initiate playback.
According to DownDetector, the issues appeared most acute in the Northeast US and Western Europe, as well as in Mexico, Australia and South America.
Multiple users in Newshub's Auckland office experienced the problem.
"Our team is aware of the issue and working on a fix. We'll follow up here with any updates," a YouTube account tweeted.
The issue appears to also be affecting related services such as YouTube TV along with the movies and TV shows people have purchased through Google TV, formerly known as Google Play Movies & TV.
Reuters / Newshub.