All three social media platforms, including Facebook Messenger, were not loading as of early Sunday afternoon.
Downdetector.com, a site that monitors site outages, shows Facebook has been down since 6:30 a.m. EST in much of the world, with thousands of reported outages concentrated in northeastern U.S., Europe and the Philippines.
It was not immediately clear what caused the outage or how long the platforms would be down.
An email requesting comment about the outage was sent to Facebook. #FacebookDown, #instagramdown and #whatsappdown were all trending on Twitter globally.
Facebook acquired Instagram in 2012 and WhatsApp in 2014. There are more than 1.52 billion daily active Facebook users, according to the social media network's website.