A spokesperson for the company told Sky News: "We're aware that some people are currently having trouble accessing the Facebook family of apps. We're working to resolve the issue as soon as possible."
Thousands of people have logged complaints on the website downdetector.com, with those using the main Facebook website and app having trouble loading their newsfeed and even logging in.
Facebook Messenger and WhatsApp are both failing to send and receive messages, and are running into other connection issues. The Instagram newsfeed is also struggling to load and update for some users.
All of the apps and services are owned and run by Facebook, which almost a month ago to the day experienced one of its longest ever outages.
The social media giant announced plans to integrate the three services back in January, prompting calls for an "urgent briefing" by the Irish data protection commissioner.
It is not clear if technical work connected to this integration is connected to the outage, although it would be an exceptional coincidence for three unconnected services to go down at the same time.
Explaining the last outage, Facebook said: "Yesterday, we made a server configuration change that triggered a cascading series of issues."
Users across the world including the US, Japan, New Zealand and parts of Europe are affected by the outage, with some reporting they have been unable to access any of Facebook, Instagram and WhatsApp for almost 24 hours.
As was the case on that occasion, many have turned to Twitter to voice their frustration, where global trending topics currently include #FacebookDown, #instagramdown and #whatsappdown.