The Wekiva River (sometimes spelled Wekiwa, a Creek word meaning "spring of water") is a 16.0-mile-long (25.7 km) river in Central Florida, north of Orlando in the United States. It originates in Apopka and joins the St. Johns River, the longest river in the state, in DeBary. The Wekiva River system includes the main stem joined by three main tributaries - Rock Springs Run, Blackwater Creek, and the Little Wekiva River - and about 30 contributing groundwater springs. It is designated as a Florida State Canoe Trail, an Outstanding Florida Water, and an Aquatic Preserve by the Florida Department of Environmental Protection. The Wekiva River system is also one of the two rivers in Florida federally designated as a National Wild and Scenic River for its scenery, recreation, geology, and diverse habitats.

Wekiwa is the Creek-Seminole word for a spring, but contrary to popular belief that Wekiva means "flowing water", it was actually an alternate spelling used by developers. The pronunciation of a soft-w, sometimes perceived as a v or b, resulted in cartographers mislabeling maps in later years. The maps drawn in 1838 and 1849 were spelled Wekiwa.

The Wekiva River system is located in three counties - Orange, Seminole, and then Lake - with a total drainage basin of 351.113 km (135.565 sq mi). The Wekiva River nearly follows the boundary between Orange and Seminole Counties. After Orange County, the river separates Lake County and Seminole County.

According to the St. Johns River Water Management District and the Geographic Names Information System, the Wekiva River originates from Wekiwa Springs, and about 3⁄4 mile (1.2 km) from the spring, Wekiva is joined by the Rock Springs Run.

The Florida Department of Environmental Protection defines the portion of the river from Wekiwa Springs to the confluence with Rock Springs Run as the Wekiwa Springs Run. The Wekiva River then starts from the confluence of the two spring runs and joins the St. Johns River after 15.3 miles (24.6 km). Other contributing springs are Sanlando Springs and Palm Springs.

The headwater of the Wekiva River is the Wekiwa Springs, a second-magnitude spring located within the Wekiwa Springs State Park in Apopka. The spring has a mean discharge of 66.5 cu ft/s (1.88 m/s) or 5,745,600 cubic feet (42,980,000 US gal) per day emanating from two vents, the largest of which is 35 by 5 ft (10.7 by 1.5 m) located 15 ft (4.6 m) under the water. A weir located about 270 ft (82 m) from the springs forms a 200-by-100-foot (61 by 30 m)-wide pool for swimming. At 170 ft (52 m) from the weir, the river widens into a trapezoidal pool about 430 ft (130 m) at its widest. The clear, bluish-green water narrows into a 60-foot (18 m)-wide run as it flows northeastward.

After only about 3⁄4 mile (1.2 km) from the headwater, the Wekiva River is joined by Rock Springs Run, a spring-fed stream that originates from Rock Springs, a second-magnitude spring located about 4 miles (6.4 km) northwest of Wekiwa Springs. Rock Springs is situated inside Kelly Park, an Orange County park in Apopka. After leaving the county park, the stream enters the Wekiwa Springs State Park, meandering for a total length of 9.2 miles (14.8 km) before joining Wekiva River. After the confluence, the area left of the Wekiva River is protected by Rock Springs Run State Reserve, another Florida state park.

A bridge to nowhere spans the river before the Wekiva Island marina about 520 yards (480 m) from the confluence with Rock Springs, the first of the two bridges that spans the river. The bridge is located at the end of Miami Springs Drive in Seminole County.

The Wekiva is joined by Seminole County's Sweetwater Creek about 1.2 mi (1.9 km) from the headwater. The 2-mile (3.2 km)-long stream is merged by the outflow of Miami Springs, a third- magnitude spring, about 800 ft (240 m) before the confluence with Wekiva River.

Beyond the creek, the eastern side of the river is protected by the Wekiva River Buffer Conservation Area, a 2,570 acres (1,040 ha) protected seasonal wetlands of lush floodplain forest of hardwoods, ferns, and sabal palms along the Wekiva and Little Wekiva Rivers. Protecting the natural condition of the area helps preserve the water quality of both rivers.

The Little Wekiva River merges with the Wekiva River about 4.7 mi (7.6 km) from the source. The 15-mile (24 km)-long Little Wekiva River is the only tributary influenced by the areas north and west of urban Orlando. The St. Johns River Water Management District has worked with the Florida Department of Environmental Protection, the Florida Department of Transportation, the city of Altamonte Springs, Seminole and Orange counties, environmental interest groups and basin residents to find solutions in rehabilitating and protecting the Little Wekiva to minimize its negative impact in the water quality of the Wekiva River. In Longwood before the Little Wekiva enters the Wekiva River Buffer Conservation Area, several second- and third-magnitude springs, including the Sanlando Springs, replenish the Little Wekiva with fresh underground water.

The State Road 46 and State Road 429 tri-spans are the only active roads that span the river with the bridges about 9 miles (14 km) from the Wekiwa Springs State Park.

The last main tributary of the Wekiva River is the 19-mile (31 km) Blackwater Creek, which joins the Wekiva about 2 miles (3.2 km) before the Wekiva joins the St. Johns River.

• List of Florida rivers

• Map of Wekiva River Aquatic Preserve
• Wekiva River at PaddleFlorida.net