The social networking site was unavailable from around 16:30 BST the day before a record number of users are predicted to use the service as the 2012 London Games kick off.
Whilst the majority of the site was unavailable, users will still granted access via the Twitter mobile site and through third-party applications.
Whilst the cause of the fault is still unknown, the company issued a message to its users addressing the downtime, which said: "Howdy folks, looks like we're expecting a small interruption of Twitter.com and some mobile clients."
In addition to this, a message posted on the Twitter network status page stated: "Our engineers are currently working to resolve the issue."
Twitter is expected to be widely used during the Olympic Games by both fans and athletes themselves.
With attendees traveling from across the world to London for the Games, it is expected that record numbers of users will flock to the social networking site to remain in contact with family and friends whilst celebrating the event.
Large scale events often lead to huge spikes in traffic for the site, such as the Euro 2012 final last month, where over 15,000 tweets were sent every second.
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