Waelder is a city in Gonzales County, Texas, United States. The population was 947 at the 2000 census. Waelder is located at 29°41′37″N 97°17′54″W / 29.69361°N 97.29833°W / 29.69361; -97.29833 (29.693658, -97.298288). According to the United States Census Bureau, the city has a total area of 1.3 square miles (3.3 km²), of which, 1.3 square miles (3.3 km²) of it is land and 0.78% is water.