The deal covers patents on a "broad range of products and technologies" that already exist and will be filed in the next 10 years, the two firms said in a joint statement.
Samsung LG's home rival and the world's top smartphone maker earlier struck a similar deal with Google in January.
"LG values its relationship with Google, and this agreement underscores both companies' commitment to developing new products and technologies that enhance consumers' lives," said J. H. Lee, executive vice president and head of the LG's intellectual property centre.
Almost all of LG's popular smartphones, tablet computers and smartwatches are powered by Android software made by the US tech giant.
LG currently the world's fourth-largest smartphone maker struggled for years with sluggish sales after making a late entry into the market.
But it recently showed signs of revival with its flagship G3 smartphones, while its bigger rival Samsung saw profits sag.
LG earlier reported an 87-percent jump in third-quarter net profit as the previously loss-making handset unit saw profits surge in a big turnaround.