The 31st Arizona State Legislature, consisting of the Arizona State Senate and the Arizona House of Representatives, was constituted in Phoenix from January 1, 1973, to December 31, 1974, during the last two years of Jack Williams' third term as Governor of Arizona. Both the Senate and the House membership remained constant at 30 and 60, respectively. The Republicans maintained their 18–12 edge in the upper house, while they increased their lead in the lower house to 38–22.
