California State Route 99

State Route 99 (SR 99), commonly known as Highway 99 or, simply, as 99 (without any further designation), is a north–south state highway in the U.S. state of California, stretching almost the entire length of the Central Valley. From its southern end at Interstate 5 (I-5) near Wheeler Ridge to its northern end at SR 36 near Red Bluff, SR 99 goes through the densely populated eastern parts of the valley. Cities served include Bakersfield, Visalia, Fresno, Madera, Merced, Modesto, Stockton, Sacramento, Turlock, Yuba City, and Chico.

The highway is a remnant of the former Mexico to Canada U.S. Route 99 (US 99), which was decommissioned after being functionally replaced by I-5 for long-distance traffic. Almost all of SR 99 south of Sacramento is a freeway, and there are plans to complete this part to Interstate Highway standards, as a parallel route to I-5 for Los Angeles–Sacramento traffic. North of Sacramento, the road ranges from a rural two-lane road to a four-lane freeway.