The 10th Legislature of the Third Portuguese Republic () ran from 10 March 2005 to 14 October 2009. The composition of the Assembly of the Republic, the legislative body of Portugal, was determined by the results of the 2005 legislative election, held on 20 February 2005. The 10th legislature was the longest in current Portuguese democracy, lasting 4 years and 218 days.
The 11th Portuguese legislative election was held on 20 February 2005. In the election, the Socialist Party (PS) won its first absolute majority.
To be elected, a candidate needs to reach a minimum of 116 votes. Jaime Gama, from the Socialist Party, was easily elected: