The 31-year-old Australian actor, wife Elsa Pataky and daughter India ran into the royal brothers at the Audi Polo Challenge on Sunday.
Hemsworth and the 38-year-old Spanish actress chatted and laughed with the English princes following the match. The actor's Avengers co-star, Samuel L. Jackson, and actors Emily Blunt, Stanley Tucci and Clive Owen were also in attendance.
Hemsworth and Pataky married in 2010, and have three children: 3-year-old India and 14-month-old twin sons Tristan and Sasha. The actress shared a photo of her husband and daughter on the polo field on Instagram, writing, "So much fun!"
Hemsworth last appeared in Avengers: Age of Ultron, and will reprise Marvel superhero Thor in Thor: Ragnarok. The actor is also scheduled for National Lampoon reboot Vacation and Snow White and the Huntsman prequel The Huntsman.