De Kalb (/dɪ ˈkæb/ di KAB) is a city in Bowie County, Texas, United States. The population was 1,699 at the 2010 census. It is part of the Texarkana, Texas – Texarkana, Arkansas Metropolitan Statistical Area. Its two area codes are 430 and 903. Its ZIP code is 75559. It is in the Central Time Zone.