The concept of zero is presented. The origin, notation and early uses of zero are described. Zero was known to the Sumerians and used by the Mayas. Greeks may have been aware of the zero concept, but they never interpreted it as a number. The introduction of zero into arithmetic is attributed to the Hindu mathematician, astronomer and poet Brahmagupta in the 7th century AD. Zero was taken over from the Hindus by the Arabs and transferred by them into Europe. An important link between the Hindu‐Arabic number system and the European mathematics is Italian mathematician Fibonacci. The vacuum problem is also discussed and its relationship with zero. Some uses of zero in mathematics (e.g. the infinitesimal method, Dirac delta function, binary number system, binary matrices), physics (e.g. origin of the Universe, laws of thermodynamics, zero temperature), chemistry (e.g. chemical equilibrium in reversible thermodynamics, quantum numbers) and biology (e.g. origin of life, biological clock) are presented. Several interesting and every‐day uses of zero are singled out and it is stressed that the mathematization of natural sciences was possibly only after zero was established as a number.