Wilmer is a city in Dallas County, Texas, United States. The population was 3,682 at the 2010 census. It is part of the Dallas–Fort Worth–Arlington Metropolitan Statistical Area.
The area was initially settled by Andrew K. Gray before 1850. The settlement was originally known as Prairie Valley when the Houston and Texas Central Railroad arrived in 1872. In 1884, the post office in Prairie Valley was renamed Wilmer, after A.J. Wilmer, a conductor on the Houston and Texas Central line. The population was estimated at 100 in 1890, with several stores and businesses operation in the community. That figure had risen to over 200 by the start of World War I. A fire destroyed most of Wilmer's business district on July 4, 1929. The community's shallow wells were unable to pump the adequate amount of water needed to extinguish the blaze.Wilmer incorporated in 1945, and its first mayor, J.H. May, was elected on a platform of installing a water system. At the time of incorporation, Wilmer had 136 homes and a population of approximately 450. In 1949, a volunteer fire department was established and a fire truck was purchased. Around the same time, Wilmer and the neighboring city of Hutchins consolidated their schools.By 1960, Wilmer was home to 1,785 residents. Throughout the latter half of the twentieth century, Wilmer continued to grow, but at a much slower rate than other communities in Dallas County. With 3,393 residents as of the 2000 census, Wilmer is currently one of the smallest incorporated cities in Dallas County.