The 34-year-old Australian actor and 41-year-old Spanish actress attended the New York premiere of 12 Strong at the Jazz at Lincoln Center.
Hemsworth showed a smile as he kept an arm around Pataky, who wore a revealing dress with a sheer design. The actress, who plays Hemsworth's character's wife, joked about her role Sunday on Instagram.
"7 years of rehearsals to play this part on @12strongmovie! Hope you will feel the chemistry," she wrote alongside a clip of herself and Hemsworth kissing and a trailer for the movie.
12 Strong co-stars Michael Shannon, Michael Peña and Trevante Rhodes, who were also present at the premiere. The film recounts the real-life story of Task Force Dagger's mission in Afghanistan following 9/11.
"Incredible premier last night in nyc for @12strongmovie, a true honour to meet the real life heroes we portrayed in the film, thanks to everyone involved," Hemsworth wrote on Instagram.
12 Strong is directed by Nicolai Fuglsig and produced by Jerry Bruckheimer, and opens in theaters Friday. Hemsworth addressed reports prior to the premiere that his brother Liam Hemsworth had married Miley Cyrus.