The 2005–06 season was the 84th season in the existence of Deportivo Alavés, and the club's first season back in the top flight of Spanish football after winning promotion from the 2004–05 Segunda División. In addition to the domestic league, Alavés participated in this season's edition of the Copa del Rey. The season covered the period from 1 July 2005 to 30 June 2006.