Lady Bird Lake, Riverside reservoir in downtown Austin, United States.

Lady Bird Lake is a river-like reservoir on the Colorado River in Austin, Texas, with a surface area of 416 acres (168 ha) and a maximum depth of 5.5 meters. It is the easternmost of the Texas Highland Lakes chain. Its banks are lined by the Ann and Roy Butler Hike-and-Bike Trail, and Zilker Park sits adjacent to the water.

The City of Austin built Longhorn Dam in 1960 to form Town Lake as a cooling pond for the Holly Street Power Plant, which ran from 1960 to 2007. Before 1971 the shoreline was mostly weeds, bushes and trash, and local station KTBC called the lake an eyesore. Mayor Roy Butler's council created the Town Lake Beautification Committee in the early 1970s and named Lady Bird Johnson honorary chairman; she gave $19,000 of her own money, and hundreds of shrubs and trees were planted.

The original name Town Lake was changed in 2007 to honor Lady Bird Johnson, the former First Lady who championed city beautification efforts. Locals gather along the shoreline for jogging, cycling, or simply watching the skyline, while rowing clubs train here regularly.

Swimming has been prohibited since 1964, but kayaking, paddleboarding, and fishing are allowed as long as only electric motors are used. The surrounding trail offers shaded sections and public access at several points along the shoreline.

Swimming is banned not because of water quality, as many assume, but because of drownings and debris from bridges and dams destroyed by past floods. Austin enacted the ban in 1964, with fines reaching $500. The lake's calm, straight course of nearly 6 miles draws university rowing teams from Wisconsin, Chicago, Oklahoma and Nebraska during winter breaks.