The Kaweah River is a river draining the southern Sierra Nevada in Tulare County, California in the United States. Fed primarily by high elevation snowmelt along the Great Western Divide, the Kaweah begins as four forks in Sequoia National Park, where the watershed is noted for its alpine scenery and its dense concentrations of giant sequoias, the largest trees on Earth. It then flows in a southwest direction to Lake Kaweah – the only major reservoir on the river – and into the San Joaquin Valley, where it diverges into multiple channels across an alluvial plain around Visalia. With its Middle Fork headwaters starting at almost 13,000 feet (4,000 m) above sea level, the river has a vertical drop of nearly two and a half miles (4.0 km) on its short run to the San Joaquin Valley, making it one of the steepest river drainages in the United States. Although the main stem of the Kaweah is only 33.6 miles (54.1 km) long, its total length including headwaters and lower branches is nearly 100 miles (160 km).

The lower course of the river and its many distributaries – including the St. John's River and Mill Creek – form the Kaweah Delta, a productive agricultural region spanning more than 300,000 acres (120,000 ha). Before the diversion of its waters for irrigation, the river flowed into Tulare Lake, the usually dry terminal sink of a large endorheic basin in the southern San Joaquin Valley, also fed by the Kern and Tule Rivers and southern branches of the Kings River.

The Yokuts and Western Mono are the main Native American groups in the Kaweah River basin, which was explored by the Spanish in the early 1800s and heavily logged after the 1850s by American colonists, before its upper reaches became part of Sequoia National Park in 1890.

The name "Kaweah" (commonly rendered as /kəˈwiːə/ kə-WEE-ə; the traditional pronunciation is /ˈɡɑːwiːhɑː/ GAH-wee-hah) comes from a native Yokutsan ethnonym for the Kaweah tribelet, traditionally said to mean "crow cry," from gá "raven" and wea "to weep." Frank F. Latta traced the etymology of gá to an onomatopoeia of a corvid's call, cf. "caw". An informant for Latta, Aida Icho, provided an idiom related to the allegedly quarrelsome nature of the (by then extinct) Kaweah:

Gawea been gone long time. Now, when crow come in tree and quarrel, we say, Gáwea, he ahm tahnse [The Gáwea have come back].”

The Kaweah River originates along the Great Western Divide, a chain of 13,000-foot (4,000 m) peaks in the middle of Sequoia National Park. The divide separates the Kaweah drainage from the Kern River drainage to the east. The Middle Fork, sometimes considered part of the main stem, flows southwest from the confluence of Lone Pine Creek and Hamilton Creek, whose lake sources lie at or above 12,000 feet (3,700 m) in the Mount Stewart area. The Middle Fork receives Cliff Creek near Redwood Meadow. The Marble Fork begins in a high plateau area known as the Tableland and drops 1,200 feet (370 m) over a glacial headwall, forming Tokopah Falls, before flowing west past Lodgepole Village and turning south. The two forks join at the bottom of a deep gorge directly below Moro Rock to form the main stem of the Kaweah River.

The Kaweah River flows in a southwest direction, paralleled by Highway 198 in its narrow canyon. A short distance outside Sequoia National Park it picks up the East Fork, which originates above 9,000 feet (2,700 m) elevation in the Mineral King valley, from the left. It continues past the town of Three Rivers, where it receives the North Fork, which begins in the Grant Grove area of Kings Canyon National Park. The South Fork enters from the left before the river empties into Lake Kaweah, the reservoir formed by Terminus Dam in the Sierra Nevada foothills. Terminus Dam, a 255-foot (78 m) high earthfill dam, has the primary purpose of flood control but also supplies water for irrigation and hydroelectricity. Below the dam the Kaweah River passes Lemon Cove, receives Dry Creek (also known as Lime Kiln Creek) from the right and flows into the San Joaquin Valley where it divides into several major distributaries.

At the McKay Point Dam, the St. John's River splits off to the northwest, making a wide loop around Visalia before becoming Cross Creek north of Goshen, from where it flows south. The main channel of the Kaweah River continues to the southwest through farmland, with Outside Creek and Deep Creek splitting to the south before the Kaweah itself divides into Mill Creek and Packwood Creek. Mill Creek continues westward through Visalia, and Packwood Creek skirts to the south of the city, terminating in a small flood control basin. Mill Creek ends at a confluence with Cross Creek, which flows southward to the old Tulare Lake bed near Corcoran, joining a channel carrying water from the Tule River. The Kaweah Delta region, as defined by the Kaweah Delta Water Conservation District, covers about 340,000 acres (140,000 ha) in Tulare and Kings Counties; the main cities are Visalia and Tulare.