He then played with the Australian national team from to . In the 1997 Intercontinental Cup, Jelks batted .471/.538/1.088 to help Australia win a bronze medal for the first time ever in a global event. He was second in average in the event behind Paul Gonzalez and tied Orestes Kindelán for the home run lead. Jelks was named on the All-Star team of the cup at designated hitter. The following year at the 1998 Baseball World Cup, he hit .278 as the starting left fielder for Australia and helped Australia to silver at the Haarlem Baseball Week. Jelks went on to play in the 1999 Intercontinental Cup and 2000 Sydney Olympics.