The 49th Arizona State Legislature, consisting of the Arizona State Senate and the Arizona House of Representatives, was constituted in Phoenix from January 1, 2009, to December 31, 2010, during the final month of Janet Napolitano's second term in office, prior to her resignation to become United States Secretary of Homeland Security, and the first two years of her successor, Jan Brewer.

The Republicans gained a seat in the Senate, increasing the majority to 18–12.

The Republicans also gained two seats in the lower chamber, giving them a 35–25 majority.

The Legislature met for two regular sessions at the State Capitol in Phoenix.

[1]: i [2]: i There were nine Special Sessions, the first of which was convened on January 28, 2009, and adjourned on January 31;[3]: 1727  the second convened on May 21, 2009, and adjourned sine die on May 27;[3]: 1785  the third convened on July 6, 2009, and adjourned sine die August 25;[3]: 1805  the fourth convened on November 17, 2009, and adjourned sine die on November 23;[3]: 2165  the fifth convened on December 17, 2009, and adjourned sine die December 19;[4]: 2475  the sixth special session convened on February 1, 2010, and adjourned sine die on February 11;[4]: 2495  the seventh special session convened on March 8, 2010, and convened sine die on March 16;[4]: 2539  the eighth special session convened on March 29, 2010, and adjourned sine die on April 1;[4]: 2823  and the ninth and final special convened on August 9, 2010, and adjourned sine die on August 11.