The 2005–06 Iran Pro League was the 23rd season of Iran's Football League and fifth as Iran Pro League since its establishment in 2001. Foolad were the defending champions. The season featured 14 teams from the 2004–05 Iran Pro League and two new teams promoted from the 2004–05 Azadegan League: Shahid Ghandi as champions and Rah Ahan as runner-up. The league started on 2 September 2005 and ended on 21 April 2006. Esteghlal won the Pro League title for the first time in their history. A total of 240 matches in the Pro League yielded 538 goals during the season.

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.