The LG G5 is an Android smartphone developed by LG Electronics as part of the LG G series. It was announced during Mobile World Congress as the successor to the 2015 LG G4. The G5 is distinguished from its predecessors by its aluminum chassis and a focus on modularity. Its lower housing, which holds the user-replaceable battery, can be slid from the bottom of the device, and replaced by alternative add-on modules that provide additional functions. Two modules are available: a camera grip, and a high-fidelity audio module with DAC. A lower-spec variation, dubbed the LG G5 SE, is available in some markets.

The LG G series was a line of Android devices produced by LG Electronics. The "G" designation was first introduced in 2012 as a branch of the LG Optimus series for flagship devices, but LG announced in July 2013 that the "Optimus" name would be discontinued for future flagships in favor of maintaining "G" and "Vu" as distinct brands. The first purely G-branded phone, the LG G2, was unveiled in August 2013.