Chronometer is a name for certain types of clock. It may refer to:

• Chronomètre of Loulié, a precursor to the metronome
• Chronometer watch, a highly accurate watch
• Marine chronometer, a timekeeper used for marine navigation, as in
  • Longitude by chronometer
• Observatory chronometer, a device certified by an observatory to be extremely accurate
• Railroad chronometer, a specialized timepiece once used for safe operation of trains

• Chronometry, the science of timekeeping
• Hydrochronometer, a water clock
• Chronograph
• Chronoscope