After months of rumour and speculation, the Korean electronics giant has officially announced a launch event at Earls Court Exhibition Centre in London on May 3 at 7pm.
The invite does not feature an image of the device to be unveiled, but simply says "Come and meet the next Galaxy".
The Galaxy S3 is part of the Samsung Mobile Unpacked 2012 event, so there could be further phones and devices announced at Earls Court next month, notes TechRadar.
Various reports to date have offered details on what consumers could expect from the new phone, which follows the 20m+ selling Galaxy S2.
The handset may feature an edge-to-edge AMOLED screen of between 4.6 and 4.8-inches, which is expected to offer a high resolution performance to rival Apple's Retina display in the iPhone.
Some reports have said that the S3 will come with a 1.5GHz dual-core processor, while others say it will be fitted with the quad-core Exynos 4412 chipset thought to be in development at Samsung.
It is likely that the smartphone will run the latest iteration of Google Android, Ice Cream Sandwich, and have a tailored version of Samsung's TouchWiz user interface layered over the top.
There are differing reports on the camera in the Galaxy S3, including some sources saying it will have a 16-megapixel camera, but others pointing to a 12MP snapper.
Other features could include wireless charging, Near Field Communications (NFC) and 4G connectivity.
> Samsung to post record quarterly profit on Galaxy boost