Robert B. Usdane[1] Republican Peter Rios[2] Democratic The 1990 Arizona Senate election was held on November 6, 1990.

Voters elected members of the Arizona Senate in all 30 of the state's legislative districts to serve a two-year term.

Primary elections were held on September 11, 1990.

[3] Prior to the elections, the Republicans held a majority of 17 seats over the Democrats' 13 seats.

[4] The newly elected senators served in the 40th Arizona State Legislature.