The Neoarchean (, also spelled Neoarchaean) is a geologic era within the Archaean. It spans the period of time from —the period being defined chronometrically and not referenced to a specific level in a rock section on Earth. Oxygenic photosynthesis first evolved in this era and was accountable for the oxygen catastrophe which was to happen later in the paleoproterozoic from a poisonous buildup of oxygen in the atmosphere, produced by these oxygen producing photoautotrophs, which evolved earlier in the Neoarchean.

br:Neoarkean ca:Neoarquià de:Neoarchaikum et:Neoarhaikum es:Era Neoarcaica fr:Néoarchéen id:Neoarkean it:Neoarcheano lt:Neoarch?jus ms:Neoarkean nl:Neoarcheïcum nn:Neoarkeikum pl:Neoarchaik pt:Neoarqueano ru:???????? sk:Neoarchaikum sh:Neoarhej fi:Neoarkeeinen maailmankausi vi:??i Tân Thái C? zh:????