Black-capped Swallow is restricted to montane regions in northern Central America, from Mexico south of the Isthmus of Tehuantepec in Chiapas through Guatemala to western Honduras and northern El Salvador (Dickey and van Rossem 1938, Miller et al. 1957, Monroe 1968, Land 1970, Thurber et al. 1987, Howell and Webb 1995).
Black-capped Swallow is primarily, if not entirely, resident. Monroe (1968) considered it to be only a nonbreeding visitor to western Honduras, but Thurber et al. (1987) found it breeding in adjacent El Salvador, and suggested that it probably bred in Honduras as well. Howell and Webb (1995) note that Black-capped Swallows "wander" in Chiapas in the nonbreeding season, and suggest that is movements require further study.
The elevational range of Black-capped Swallow is reported as 1000-3000 m (Howell and Webb 1995) and as 1600-3100 m (Parker et al. 1996).