The operating system upgrade was confirmed for the previous-generation device on the company's Korea website, but a release date was not announced.
Android 4.1 will introduce a raft of new features to the Galaxy S2, such as swifter navigation speeds and the Google Now personal assistant.
Software features that debuted on the Samsung Galaxy S3, including Smart Stay, Pop-Up Play and the option to pause recordings on the camera app, will also be included in the update.
The download will take up 1GB of additional space on users' handsets and take up to one hour to download.
Last week, what is rumoured to be a press shot of the Samsung Galaxy S4 appeared online.