The firm tweeted: "All PSN services have been restored. Thank you for your patience."
No explanation has been offered for the outage.
PlayStation Network is currently experiencing issues, while for some it is down entirely.
Many users found on Thursday that they are unable to use certain PSN features, with denied access to the PSN Store being the most common issue.
Sony has issued a response on the UK PlayStation technical support forums, saying that it is aware of the problem and is investigating how to fix it.
"At the moment PlayStation Network is currently experiencing issues and some users may encounter problems with network services and the store. (An error code e.g. 80023102 may appear when trying to sign in)," read the statement.
"Engineers are currently investigating the cause of these problems, and I will update here when more information is available."
PlayStation's US support forums issued a shorter statement referring to the issue as "unplanned maintenance".