The two met in January 2005 at the annual G'Day LA: Australia Week gala in Los Angeles. Urban, 48, took to Instagram to share a picture from the event.
"Our very first photo together 2005, minutes after being introduced to each other," he wrote. "HAPPY ANNIVERSARY BABY. LOVE YOU! KU," he captioned the picture.
The 49-year-old Oscar-winning actress attended the party with her sister Antonia and wore a glittering black fringe dress. The musician was dressed in a black velvet sports jacket and collared shirt. Producer Kerry Roberts introduced Urban to Kidman.