The 5th Sejm (lower house of the Polish legislature) was elected on 25 September 2005 at the 2005 Polish parliamentary election.

The term lasted between 19 October 2005 and 4 November 2007, two years before mandatory end of its four year term,[1] as the chamber decided to dissolve itself on 7 September 2007.

[2] The Marshal of the Sejm was elected on the second day of the first session, that is on 26 October 2006, thus Senior Marshal Józef Zych served for seven days.

[3][4] On 4 November 2007, at the end of the term, deputies were affiliated with the following parliamentary clubs (klub) and caucuses (koło):[15]