The 2012 Arizona Senate election was held on November 6, 2012. Voters elected members of the Arizona Senate in all 30 of the state's legislative districts to serve a two-year term. These were the first elections following the 2010 redistricting cycle. Since passage of Proposition 106 in 2000, redistricting in Arizona is done by the Arizona Independent Redistricting Commission (AIRC). Following redistricting, many incumbents were moved into new districts. Primary elections were held on August 28, 2012.

Prior to the elections, the Republicans held a majority of 21 seats over the Democrats' nine seats.

Following the election, Republicans maintained control of the chamber with 17 Republicans to 13 Democrats, a net gain of four seats for Democrats.

The newly elected senators served in the 51st Arizona State Legislature.

Republican Senate President Russell Pearce faced a recall election on November 8, 2011. For the first time in Arizona history, a member of the state legislature was ousted from the body in a recall. Fellow Republican Jerry Lewis defeated Pearce and took his seat in the Senate. Official election results here.