Bogut was born in Melbourne in 1984. His parents, Michael and Anne, had immigrated to Australia from Croatia in the 1970s. Bogut grew up playing Australian rules football and tennis in addition to basketball. As a child, he patterned his basketball game after Toni Kukoč, a Croatian NBA player who spent the majority of the 1990s playing for the Chicago Bulls. As a 15-year-old, he was cut from the Victoria junior state representative team. In response to this setback, Bogut began to improve his game with the help of Siniša Marković, a professional basketball player from Yugoslavia. Bogut's emergence began after he earned a roster spot with the Australian Institute of Sport (AIS) in 2002. He competed in the South East Australian Basketball League (SEABL) in 2002 and 2003, helping the AIS win the East Conference title in his first season. He later joined the U-19 Australian junior national team, and was named the most valuable player of the 2003 FIBA Under-19 World Cup, in Greece, after leading the Emus to the title. In eight games, he averaged 26. 3 points, 17 rebounds, 2. 5 assists and 1. 5 blocks per game, and he shot 61 percent from the field and 74 percent from the free throw line. One of the highlights of his MVP conquest was a 22-point, 18-rebound performance, in a 106–85 win over the US, in the quarter-finals of the medal round.