The 2004–05 Iran Pro League was the 22nd season of Iran's Football League and fourth as Iran Pro League since its establishment in 2001. PAS Tehran were the defending champions. The season featured 14 teams from the 2003–04 Iran Pro League and two new teams promoted from the 2003–04 Azadegan League. The two teams were the last seasons league champions Saba Battery and runners-up Malavan. The league started on 13 September 2004 and ended on 20 June 2005. Foolad won the Pro League title for the first time in their history.

The Persian Gulf Pro League, formerly known as the Iran Premier League, is the highest division of professional football in Iran. Each year, its top team becomes the Iranian football champion, and the two lowest finishers are relegated to Azadegan League.