The Sprint LG Optimus G is getting a nice upgrade to Jelly Bean with numerous reports of the update rolling out to owners. While it's only been a little over three months since the phone's release, Jelly Bean has been available on devices as early as July 2012. The LG Optimus G on the other hand, launched on Sprint's network back in November running Android 4.0.4 Ice Cream Sandwich. There is no official word from Sprint if it's a large or more gradual roll-out, but you can see if you have the update right now by navigating to your settings and selecting “About Phone” and looking for the software update from there. If you do manage to grab the update, you'll finally get upgraded to 4.1.2 Jelly Bean. If not, then sit tight as you will probably get the update eventually.
Source: Phandroid