Waelder is a city in Gonzales County, Texas, United States. The population was 1065 at the 2010 census.
Waelder is located at 29°41′37″N 97°17′54″W (29.693658, -97.298288).
According to the United States Census Bureau, the city has a total area of 1.3 square miles (3.4 km2), of which, 1.3 square miles (3.4 km2) of it is land and 0.78% is water.
The climate in this area is characterized by hot, humid summers and generally mild to cool winters. According to the Köppen Climate Classification system, Waelder has a humid subtropical climate, abbreviated "Cfa" on climate maps.