Lakeshore Records released Barely Lethal Original Motion Picture Soundtrack, featuring the original music composed by Mateo Messina. The recording was released digitally on June 9, 2015 and will be available on CD later this year.

"The protagonist is a badass secret agent, but at the same time she's a teenage girl who just wants to fit in," said Messina. "I wanted to honor all of her 'inner badass' while still playing her vulnerability as a teenager."

"The viewer begins this film in an intense world of spies, action, training, drama, and just a lot of fighting with fists, feet, and guns," explained Messina. "But then we transition to an entire new world, the small Anywhere American town of Newton. Despite the difference, this mundane little town is the greatest place in the world to Megan. The score had to reflect the town's small-time charm without feeling like too much of a disconnect from the rest of the world. While I switched up the style and instrumentation dramatically, I made sure there were hints of our theme inside it melodically so viewers would always be a connected to the whole story just as Megan is."

"I loved how the film (and the script) felt like it shot you out of a cannon into the action," Messina described. "With pacing taken care of, we focused a lot of our attention on tone. Seeing the protagonist's obsession with 80's and 90's teen movies as her way of learning how to socialize with the rest of the world keyed me into pitching director Kyle Newman a score that uses 80's and 90's analog synths to their best effect."