The Johannesburg Dome, located in the central part of the Kaapvaal Craton, constitutes one of the key areas to better understand the Archaean crustal evolution of this part of the craton. The dome comprises a variety of Archaean granitic rocks intruded into mafic–ultramafic greenstone remnants. This study presents new precise U–Pb single zircon dating for seven different granitoid samples and an amphibolite dyke collected from the Johannesburg Dome. A trondhjemitic gneiss sampled on the northwestern part of the dome yielded an age of 3340±3 Ma and represents the oldest granitoid phase recognized so far. This result has important implications with regard to the age of the mafic and ultramafic greenstone remnants scattered throughout the dome as it implies that the greenstone remnants are older than c.3.34 Ga. This initial magmatic episode, involving early greenstone development and the intrusion of trondhjemitic and tonalitic granitoids on the northern half of the dome, was followed by the emplacement of a 3201±5 Ma hornblende–biotite–tonalite gneiss in the south. Following the trondhjemite–tonalite gneiss emplacement a further period of magmatism took place on the dome, which resulted in the intrusion of mafic dykes that are manifest as hornblende amphibolites. The age of these dykes has yet to be determined quantitatively, but they fall within the time constraints imposed by the age of the trondhjemitic gneisses (3340–3200 Ma) and later, crosscutting, potassic granitoids. These rocks, consisting dominantly of granodiorites constitute the third magmatic event and occupy an area of batholithic dimensions extending across most of the southern portion of the dome. The southern and southeastern parts of the batholith consist mainly of medium-grained, homogeneous, grey granodiorites dated at 3121±5 Ma. Their porphyritic granodiorite equivalents in the southwestern part of the dome yielded an age of 3114±2.3 Ma. An age of 3117±12 Ma, from zircons extracted from one of the mafic dykes possessing granitic microveins, provided confirmation of the timing of this third magmatic event. Lastly, pegmatites that crosscut all these earlier granitoid events are younger than 3114 Ma and might be at least 3.0 billion-years old. These new data provide confirmation of the conclusion that the Witwatersrand Basin was deposited after c.3074 Ma on an Archaean basement as young as c.3120 Ma. The data, combined with that from other parts of the Kaapvaal Craton, further supports the view that the evolution of the Craton was long-lived and episodic, and that it grew by accretionary processes, becoming generally younger to the north and west of the c.3.5 Ga Barberton-Swaziland granite–greenstone terrane situated in the southeastern part of the Craton.