Big Brother (Australian TV series) season 3

The third season of the Australian reality television series, Big Brother, also known as Big Brother 2003, lasted 86 days, starting on 27 April 2003 and ending on 21 July 2003. The winner of season 3 was Regina Bird. Regina earned public admiration with her down-to-earth charm and work ethic. Chrissie Swan was the runner-up for the season and has excelled as an entertainment and media personality since. Bird was the first female winner of the show.

The season follows the same basic format at the prior season - however the twist for the season had housemates starting their Big Brother experience in two separate houses - a "Round House" and a "Square House". On Night 22, all Housemates were locked into their respective bedrooms and a construction crew spent the night merging the two houses and revealing the hidden swimming pool and kitchen that had been in between the two smaller houses. Housemates were released into their new combined house on the morning of Day 23. Later in the day, a bathroom linking the two bedrooms was revealed. This was also the first season in which cameras were completely hidden for the first time in this season. Previously some cameras were visible to housemates and at times housemates were aware of the camera tracking their movements.