Fossil Creek (Yavapai: Hakhavsuwa or Vialnyucha) is a perennial stream accessed by a forest road near the community of Camp Verde in the U.S. state of Arizona. Access is from Forest Road 708 off Arizona State Route 260 east of Camp Verde. A tributary of the Verde River, Fossil Creek flows from its headwaters on the Mogollon Rim to meet the larger stream near the former Childs Power Plant.

Fossil Springs, near the headwaters, emits upwards of 20,000 US gallons (76 m³) per minute that flow into the creek year-round. Calcium carbonate, precipitating from the 72 °F (22 °C) water from the springs, creates travertine dams and deposits for several miles downstream. The Fossil Creek system is the fourth largest producer of travertine in the United States.

Fossil Creek is one of only two streams in Arizona included in the National Wild and Scenic Rivers System. The creek and its riparian corridor provide habitat for a wide variety of flora and fauna, some listed as endangered or otherwise imperiled. Its former power-plant complex is listed as a National Historic District. Since restoration of the stream's natural flow in 2008, an increase in recreational visits has raised concerns about overuse and has led to road closings and other restrictions.

Fossil Springs, the head water of Fossil Creek, arises at an elevation of 6,510 feet (1,980 m) above sea level on the Mogollon Rim in Coconino County north of Strawberry. For about the first 3 miles (5 km), the creek's flow is intermittent.

From high on the rim, the creek runs generally north, entering Gila County almost immediately. It continues north through the wilderness to the confluence of an intermittent stream in Calf Pen Canyon, which enters from the right. Turning west, the creek receives another intermittent stream from the right in Sandrock Canyon, at the head of Fossil Creek Canyon. Before it reaches Fossil Springs, the creek becomes the boundary between Gila County on the stream's left and Yavapai County on its right, and it remains the boundary all the way to the Verde River.

The perennial stretches of the stream begin at Fossil Springs, at river mile (RM) 14 or river kilometer (RK) 23, in the Fossil Springs Wilderness of the Coconino National Forest at an elevation of about 4,100 feet (1,200 m). Below the springs, the creek flows west and southwest, passing the remnants of a former dam. Unnamed intermittent streams enter from left and right. Before Fossil Creek reaches the former Irving Power Plant, it leaves the Fossil Springs Wilderness, and below the plant, it enters the Mazatzal Wilderness of the Tonto National Forest. Forest Road 708 (Fossil Creek Road) follows the creek for 2.5 miles (4.0 km) along this stretch, crossing the creek once at Fossil Creek Bridge.

After Cimarron Creek Wash enters from the right, Fossil Creek turns sharply south. In the next stretch, Stehr Lakebed (dry) is to the right and Deadman Mesa to the left. Hardscrabble Creek enters from the left just before Fossil Creek turns west again and enters the Verde River.

The flow of water from Fossil Springs has been estimated to range from 43 to 56 cubic feet per second (1.2 to 1.6 m³/s) (320–420 gal/s) year-round, and it emerges from underground at a constant 72 °F (22 °C). The United States Geological Survey installed a stream gauge at the Fossil Creek Bridge in 2010. The maximum daily discharge at that station was 885 cubic feet per second (25.1 m³/s) on February 19, 2011, and the minimum was 39 cubic feet per second (1.1 m³/s) on August 6, 2011.