Concepción (Spanish for "conception", in reference to the Immaculate Conception of Roman Catholic dogma) is the name of several towns and cities (the largest of which is Concepción, Chile, conurbation of which houses over one million people) :
*Argentina
**Concepción del Uruguay, Entre Ríos
**Concepción de la Sierra Department, Misiones
**Concepción de la Sierra
**Concepción Department, Corrientes
**Concepción, Corrientes
*Chile
**Concepción Province, Chile
**Concepción, Chile
*Colombia
**Concepción, Colombia, Santander
*Guatemala
**Concepción Chiquirichapa
**Concepción Huista
**Concepción Las Minas
**Concepción Tutuapa
**Concepción, Sololá
*Mexico
**Concepción, Campeche
**Concepción, Tabasco
*Paraguay
**Concepción, Paraguay
*Peru
**Concepción Province, Peru
**Concepción, Junín
*Philippines
** Concepcion, Iloilo
** Concepcion, Misamis Occidental
** Concepcion, Romblon
** Concepcion, Tarlac
*Venezuela
**Concepción, Zulia
*United States
**Nuestra Senora de la Purisima Concepcion de Acuna, Texas

Also:
*Concepción (volcano) - A volcano in Nicaragua
*Battle of Concepción - A battle in the Texas War of Independence
*Concepción (Ship) - A ship in the Chilean Navy