It includes many of the suburbs north and west of Phoenix, in Maricopa County, Arizona.

[4] It is the geographic and demographic successor of the old 2nd; while the 4th district contains most of the old 2nd's land, more than 92 percent of the old 2nd's constituents were drawn into the 8th.

Longtime Republican incumbent Jim Kolbe retired in 2007, and was succeeded by Democrat Gabby Giffords, who was shot and severely wounded at a public event on January 8, 2011.

The 8th was redrawn to include nearly all of the Maricopa County portion of the old 2nd district–as mentioned above, more than 92 percent of the old 2nd's population.

For the 118th and successive Congresses (based on redistricting following the 2020 census), the district contains all or portions of following counties and communities.