William Smillie, a talented actor hailing from Chicago, carved out a notable career largely through his involvement in productions based in his hometown. William Smillie trained in improvisational comedy at the renowned iO—also known as the Improv Olympic—in Chicago, which helped lay the foundation for his acting journey. His big break came in 2008 when he made both his professional acting debut and feature film appearance in The Dark Knight. In that film, William Smillie portrayed one of the Joker’s henchmen, recognizable by the eerie clown mask he wore during the movie’s intense opening bank heist scene—a sequence famously filmed right in the heart of Chicago.

That same year, William Smillie stepped into the world of television with a guest appearance on the long-running medical drama ER, which aired on NBC. As his career progressed, he continued to build strong ties with Chicago-based projects. In 2011, he appeared in The Dilemma, a comedy starring Vince Vaughn and Kevin James—another film shot on location in Chicago. Around the same time, William Smillie took on a two-episode role in the short-lived but critically acclaimed series The Chicago Code on Fox.

His connection to the city’s television landscape deepened when he joined the cast of Chicago Fire (NBC, 2012–present), where he portrayed the recurring character Hadley. Fans of William Smillie would later see him take on a more central role when he became part of the main cast of the police procedural APB, which aired on Fox in 2017. Throughout his career, William Smillie consistently brought authenticity and depth to roles rooted in the urban fabric of Chicago, making him a familiar face in the city’s entertainment scene.