On November 3, 2016, Rupert Gregson-Williams was hired to write and compose the film's music. He was joined by Evan Jolly, Tom Howe, Paul Mounsey, and Andrew Kawczynski, who provided additional music. The soundtrack was released on CD, digital, and vinyl the same day as the film. Australian musician Sia sang a song for the film, titled "To Be Human", featuring English musician Labrinth. Written by Florence Welch and Rick Nowels, the track is also featured on the soundtrack. The soundtrack also features samples from Wonder Woman's theme "Is She with You" from the Batman v Superman: Dawn of Justice soundtrack composed by Hans Zimmer and Junkie XL.
In late 2013, Zack Snyder cast Gal Gadot in the role of Wonder Woman for the 2016 film, Batman v Superman: Dawn of Justice over Élodie Yung and Olga Kurylenko. Some fans initially reacted to this choice by criticizing Gadot's appearance. Snyder would later comment on his decision to cast Gadot, stating that he tested a "bunch of actresses, as you can imagine. But the thing with Gal is that she's strong, she's beautiful, and she's a kind person, which is interesting, but fierce at the same time. It's that combination of being fierce but kind at the same time that we were looking for. Gadot described Diana as having "the heart of a human so she can be emotional, she's curious, she's compassionate, she loves people. And then she has the powers of a goddess. She's all for good, she fights for good." She also said that Diana has "many strengths and powers, but at the end of the day she's a woman with a lot of emotional intelligence". As to how her character is different from her appearance in Batman v Superman: Dawn of Justice, Gadot said "We go back 100 years to when she's more naive", further explaining, "She's this young idealist. She's pure. Very different to the experienced, super-confident, grown-up woman you've seen". Gadot underwent a diet and training regimen, practiced different martial arts and gained 17 pounds of muscle for the role. Gadot was previously offered a different role (as a villain) in Man of Steel, which she declined because she was pregnant at the time; this allowed her to later be cast as Wonder Woman in the film's follow-up. Gadot signed a three-picture deal. She was paid a base salary of $300,000 for the film itself.
In one episode, a newspaper editor named Brown, desperate to discover Wonder Woman’s past, assigns a team of reporters to chase her down; she easily escapes them. Brown, gone half mad, is committed to a hospital. Wonder Woman disguises herself as a nurse and brings him a scroll. “This parchment seems to be the history of that girl you call ‘Wonder Woman’!” she tells him. “A strange, veiled woman left it with me.” Brown leaps out of bed and races back to the city desk, where he cries out, parchment in hand, “Stop the presses! I’ve got the history of Wonder Woman!” But Wonder Woman’s secret history isn’t written on parchment. Instead, it lies buried in boxes and cabinets and drawers, in thousands of documents, housed in libraries, archives and collections spread all over the United States, including the private papers of creator Marston—papers that, before I saw them, had never before been seen by anyone outside of Marston’s family.