Imagine Dragons frontman Dan Reynolds married Aja Volkman, lead singer of the band Nico Vega, on March 5, 2011. On April 26, 2018, Reynolds announced that he and Volkman would be getting a divorce, but the couple decided to hold off from signing the divorce papers and got back together again. Reynolds and Volkman wrote this vulnerable rock ballad about their frayed relationship before their separation. Oh, hush, my dear, it's been a difficult year And terrors don't prey on innocent victims Trust me, darlin', trust me darlin' It's been a loveless year "Bad Liar" was released on November 6, 2018, the same day that Reynolds and Volkman announced they were dating once again.

Reynolds first met Aja Volkman when Imagine Dragons were invited to perform as an opening set for Nico Vega in 2010. The pair began collaborating and formed a duo, known as Egyptian, which released a self-titled EP in 2011. Though this is their first written collaboration made available to the public since then, Volkman has been the muse on several songs Reynolds has written for Imagine Dragons, including "It Comes Back to You" and "Next To Me."

The song was produced by Jorgen Odegard, who also helmed Hailee Steinfeld's electro-pop track "Back To Life." Odegard has previously remixed several of Imagine Dragons' numbers, including "Gold" and "Whatever It Takes."