Carlsbad or Karlsbad is a German placename meaning "Charles's spa", named after Charles IV, Holy Roman Emperor (1316–1378).
Carlsbad or Karlsbad may also refer to:
- Carlsbad, California, United States
- Carlsbad, New Mexico, United States
- Carlsbad, Texas, United States
- Karlovy Vary, Czech Republic (formerly known by its German name Karlsbad, known as Carlsbad in English)
- Karlsbad (Baden), Germany