Tooele City is located thirty-two miles southwest of Salt Lake City at the western base of the Oquirrh Mountains, which form the eastern border of the city. To the west lies the Stansbury Range; to the north twelve miles is the Great Salt Lake; and on the south, a low divide, Stockton Pass, separates Tooele from Rush Valley.

Tooele is the county's largest city, and took its name from the valley, which Captain Howard Stansbury spelled "tuilla" on his surveying maps in 1849-50. The name possibly originates from Indians known to early pioneers as "Tooelians," who lived in the area, although others claim it comes from the Spanish word for a bulrush plant found in the area.